tag:blogger.com,1999:blog-42589128484024664592024-02-08T03:54:29.136-08:00Reviews and essays 2Carlos Miguel Albuquerquehttp://www.blogger.com/profile/15403916224472065107noreply@blogger.comBlogger13125tag:blogger.com,1999:blog-4258912848402466459.post-2154763285159987252009-04-10T10:47:00.001-07:002009-04-11T13:32:44.082-07:00Pterosaur essayBasically an essay for my personal project (as well as for JPL's "New Dinosaurs").<br />------------------------------------------------------------------------------------------<br />Out of all flying vertebrates that ever lived, pterosaurs are probably the most impressive ones. Specialized winged sauropsids, these produced the largest fliers ever, and produced an unique set of adaptations for life in the air. Their wings are composed of a complex membrane composed of not only skin, but also muscle and collagen fibers (used to make it stronger and keep its shape while flying), and that is supported by the arm and a very long fourth finger, that is attached to the body and extended along it until the ankles. In addition they also have a smaller membrane that attaches to the shoulder and runs across the arm (propatagium), which ends on an elongated wrist bone known as pteroyd, used in the same way as birds use their allula; another membrane runs along the legs (uropatagium). Pterosaurs have an air sac pulmonary system, pretty much like dinosaurs, very efficient for the high oxygen demands of their warm blooded metabolism. The advanced pterodactyloid pterosaurs have also other adaptations for flight, such as a nasoanteorbital frenestra (a fusion of the nostril with the anteorbital frenestra, a "hole" in the skull of archosaurs between the nostril and the orbit), a notarium (a fusion of dorsal vertebrae, used to stabilize the body during flight), long metacarpals (so that the weight of the wing membrane doesn't fall all on the wing finger; it also aids on terrestrial locomotion) and short tail; more advanced species also lack teeth. Pterosaurs reproduce via egg laying, burrying their eggs on the ground. While some species might show parental care, the "flaplings" are nonetheless precocial, being able to fly since they are born, and because they already start looking for food they occupy several niches across their lifetime (which means a smaller species diversity compared to birds)<br /><br /><br /><br />Pterosaurs first appeared in the Triassic, as long tailed primitive forms such as Eudimorphodon. They seem to have had evolved from basal ornithodirans like Lagosuchus, which also gave rise to dinosaurs. Soon they dominated the air, and these basal forms became very diverse until the end of the Jurassic, when the first pterodactyloids evolved; indeed, only anurognathids seemed to had survived. Pterodactyloids soon diversified, producing a larger amount of species taking over a lot more niches. Then, towards the middle Cretaceous, they seemed to that been declining, as only the larger genera appear in the fossil record; however, smaller ones did had survived, only that they were sheldomly preserved in the fossil record (at least until the Eocene, when they reappear in laggerstaten fossil sites like Messel, absent from the late Cretaceous). As the Cenezoic came, they preserved a middle diversity; the <strong>Paleocene/Eocene Thermal Maximum</strong> exterminated the pelagic pteranodonts, while the later Pliocene cooling caused extinctions in Europe and (to a lesser extent) in North America. Nonetheless, pterosaurs are still common and recolonised the regions they had disappeared from in the interglacial periods.<br /><span style="font-size:180%;"></span><br /><span style="font-size:180%;">Anurognathoidea</span><br /><br />The most basal living pterosaurs, and a somewhat poorly understood linage. Mainly nocturnal fliers, they avoid competion with pterodactyloids, and took a nightjar like lifestyle, feeding on moths and other night flying insects. Relying on vision to guide themselves, they share their environment with volaticothere mammals (bat analogues), which use sonar to find their way in the dark; anurognathids also have often bristles to sense the vibrations of flying insects, and down on their wing membranes in order to decrease the sound created by the wing flapping. Anurognathids are for all purposes Caprimulgiforme analogues, having a broad, short snout like insectivore birds have short and broad bills (making their heads somewhat frog like); they also have bigger uropatagia than pterodactyloids, supported by a very long first toe, acting like a the forked tail of insectivore birds. While there's not a lot of species diversity (35+) the ones present are quite common.<br /><br /><span style="font-size:130%;"></span><br /><span style="font-size:130%;">Anurognathidae</span><br /><br /><br />The typical anurognathoids, nocturnal animals with short and broad wings that live in forests. Barely changed since the Mesozoic, they are mostly aerial insectivores, but some became vertebrate predators like our world's frogmouths, and a particular species, the <strong>Cliff Ghast</strong> (<em>Daemonognathus phillippullmani</em>) became a large diurnal scavenger/predator from Eurasian mountain ranges, competing with predatory birds.<br /><span style="font-size:130%;"></span><br /><span style="font-size:130%;">Ranorhynchidae</span><br /><br />Although the earliest members of this clade seem to have first appeared in the Eocene, genetic data indicates a much older origin, probably dating from the Cretaceous or even earlier (though its unlikely modern looking species evolved prior to the Paleocene/Eocene periods. Unlike their more conservative relatives, they are diurnal, and so they lost adaptations like the down covered wing membranes and bristles, and have longer and thinner wings. As a whole, they resemble pterosaurian swallows (ence their english name, "swallow lizards"), and that even reflects itself where they lay their eggs; rather than burrying them, they actually build nests not too different from those of our world's swallows, keeping inaccessible to ground dweeling predators. There are more or less 13 species of these fliers divided in two genera, <em>Hirundosaurus</em> and <em>Ranorhynchus</em>, the first more common in Eurasia, Africa and the Americas while the other being restricted to Ocenia and Pacific islands (and yet with a larger species count).<br /><br /><span style="font-size:180%;">Pterodactyloidea</span><br /><br /><br />The rest of the living pterosaurs belong to this clade, which has developed several adaptations absent in more basal pterosaurs as mentioned in the first paragraph of this essay.<br /><br /><br /><span style="font-size:130%;">Ctenochasmatoidea</span><br /><br />A basal linage of pterodactyloids which included the famous <em>Pterodactylus</em>, they are notorious for their wading habits, having evolved large webbed feet for that purpose. Although they produced stork and heron like forms in the past, they all modern species (and most extinct ones) are filter feeders, using very thin and numerous teeth to trap small animals in their beaks. Smaller forms managed to survive in the Cretaceous, barely becoming preserved, and they only reappered significantly in the Eocene, when laggerstaten fossil sites also reappeared. Relatively more common in the northern hemisphere, they suffered a heavy blow when the ice ages came. Now days, a few species still exist, forming large flocks in wetland areas like flamingoes.<br /><span style="font-size:130%;"></span><br /><span style="font-size:130%;">Ornithocheiroidea</span><br /><br />Having declined since the Cretaceous, they are now reduced to a two cryptic species, the african <strong>Kongamato</strong> (<em>Amphipterus africanus</em>) and the <strong>Ropen</strong> (<em>Lucipterosaurus aumalae</em>). Both are aerial predators from rainforest and wetland areas, preying on small tetrapods and fish. They seem to be both solitary; the Kongamato is highly territorial and agressive, often attacking large animals that happen to be on their nesting sites. Little is known about the Ropen; it seems to be nocturnal, and its wing membranes glow due to a symbiotic relationship with a special specie of fungus.<br /><br /><span style="font-size:130%;">Azhdarchoidea</span><br /><br />Probably the most diverse linage of modern pterosaurs aside from anurognathids. Represented as the huge azhdarchids during the late Cretaceous, the globalization of rainforests drove the large species to polar areas or coastoal zones, since they couldn't live in the dense forests. The end result was that these pterosaurs diverged into three separate clades:<br /><br /><strong>Neoazhdarchidae</strong><br /><br />Relatively conservative forms, they are hardly different from their Cretaceous relatives. They are divided into five species and their range pretty much covers all of the large landmasses.<br /><br /><strong>Eunemicolopteridae</strong><br /><br />During the Eocene, a linage of azhdarchids decreased drastically in size via neoteny (since pterosaurs are highly precocial and occupy many niches across their lifetime, it would be fairly easy for them to start reproducing at an earlier stage of their lives and not needing to grow besides that phase anymore). Having specialized to a life in rainforests, these relatively small pterosaurs occupy niches occupied in our world by hornbills and toucans; this situation is rather the inverse than in our world's hornbills, as while grassland dweeling pterosaurs produced rainforest forms while rainforest dweeling hornbills produced savanna dweeling forms.<br /><br /><strong>Apterocheiridae</strong><br /><br />Also in the Eocene, a linage of azhdarchids became isolated in Africa (then an island) and lost their ability to fly. Their wing membranes were lost (aside from a small membrane supported by a very reduced wing finger), and the usually plantigrade pterosaurian hind feet became digitigrade, just like the front ones (though not to that extreme). Their front feet (in a lateral position in most pterosaurs) also rotated forward, and their bodies became more robust. Being omnivores with carnivore tendencies, they took over the niches of oviraptors in Eurasia after the colision of Africa with that continent. In the americas, though, non-avimimid oviraptors (since avimimids took over small ornithopod niches) still remained somewhat dominant, specially after the interchange with South America that occured in the Pliocene. Apterocheirids are quite bizarre in the way how they reproduce; because pterosaurs lay eggs with very thin shells, ovivipary managed to evolve in these flightless forms, something that birds can't evolve due to their hard shelled eggs. Juveniles are protected by the parents, but more basal forms (most insular) don't display it; instead, the juveniles take an arboreal lifestyle, using wing membranes to glide (they later disappear aside from the vestigial structure, mentioned before)<br /><br /><em><strong>[I'll give specie examples later]</strong></em>Carlos Miguel Albuquerquehttp://www.blogger.com/profile/15403916224472065107noreply@blogger.com0tag:blogger.com,1999:blog-4258912848402466459.post-15938380407491381542009-03-21T05:19:00.000-07:002009-03-24T02:12:33.903-07:00Cenozoic PterosaursThis topic is about speculative biology, so if you're a cryptozoologist, well, no cookies for ya. Okay, maybe, but not for creationists who uselessly attempt to use supposed living pterosaurs as evidence against evolution. JTFFDP (Já Te Fodi, Filho/a Da Puta [portuguese sentence, so usefull for insulting])<br />----------------------------------------------------------------------------------------<br /><br />As you can possibly imagine, speculating about a world were the K-T event didn't occured brings pterosaurs into the conversation.<br /><br />The situation of these flying sauropsids in the Cretaceous is somewhat controversial; it is pretty obvious they achieved their golden age in the Early Cretaceous, when pterodactyloids produced a gigantic variety of forms, following the demise of basal pterosaurs, though anurognathids are present in laggerstaten fossil sites which only date in the Mesozoic from the Late Jurassic and Early Cretaceous (see below); interestingly, <strong>most</strong> ctenochasmatoid pterodactyloids also were found in laggerstaten fossil sites (again, see below). Pratically all pterodactyloid clades (aside from azhdarchids and pteranodontians) date from this era, and diversification within such clades is quite evident, specially in ctenochasmatoids, ranging from the very specialized filter feeder<em> Pterodaustro</em> to the equally specialized fisher <em>Cearadactylus</em>. Other clades show less extreme variations, but still notable (note the difference from the fishing ornithocheirids and the scavenging istiodactylids, both within Ornithocheiroidea).<br /><br />Then, the fossil record seems to suggest a sudden disappearence of clades, and so only lonchodectids, ornithocheirids, pteranodontids and azhdarchids make it into the Late Cretaceous, and out of these only two clades survived beyond the Turonian (however, I pretty much assume the two last clades outcompeted the first two, since pteranodonts and azhdarchs only became notable in the late Cretaceous, following the dcline of the previous two clades). This, obviously, could be seen as that pterosaurs were suddenly declining and in the way of meeting a dire fate...<br /><br /><strong>However</strong>, this might not be the case. As pointed out before, anurognathids are only known from laggerstaten fossil sites, and they appear in the Early Cretaceous, not just on the Late Jurassic. As a whole, these clade might actually have had a history as a Lazarus taxon, because all evidence points for a Triassic origin (they were the most basal known pterosaurs), and yet we lack Triassic fossils (and Triassic laggerstaten). Thus, its possible that they endured until the K-T event. Also, note that ctenochasmatoids were also mainly found in laggerstaten, thus probably also implying that they endured until the end.<br /><br />Thus that leaves us with what? Four clades? Enough for me. Out of these clades, I'm assuming most would survive into the Cenozoic, had the asteroid not collided and ruined all the fun, except perhaps pteranodontians, because they were very specialized to a pelagic lifestyle, and the Paelocene/Eocene Thermal Maximum would probably exterminate them, as oceans are specially sensitive to climatic changes so extreme as those. Even if they survive they wouldn't pass the Eocene/Oligocene extinction event anyway. Of course, they could become smaller via neoteny, thus being reduced to small, adaptable forms. Whatever.<br /><br />The other pterosaurs, well more adaptable, would obviously survive and diversify. In particular I can see a pterosaur diversity radiation lasting from the Eocene to the Miocene. Then, with the cooling of the climate, I'm assuming the flying reptiles would be hitten. Probably death to european and perhaps north american denizens, and the survivors could colonise those lands from the south, once the climate became warmer (such cycles, between retreat and return, would occur many times, since there were at least 32 ice ages in the last 2 million years).<br /><br />Flightlessness in pterosaurs is likely, specially in azhdarchids and/or ctenochasmatoids, but I'd expect it to evolve only one or two times; bats never produced flightless forms after all, and while I <strong>hate</strong> the bat/pterosaur comparation I do have to agree that both were similar in one thing: the wing membrane, which extended unto the legs, would make it more difficult for them to produce fully flightless forms (birds, on the other hand, only need to loose the wing feathers to be flightless; they have their legs seperated from the wings after all). However, because pterodactyloids had reduced uropatagia, and an upright leg stance (like mammals and dinosaurs), it makes a flightless pterosaur more plausible than a flightless bat. For more info on wingless pterosaurs, see Darren Naish's post:<br /><br /><a href="http://scienceblogs.com/tetrapodzoology/2008/09/come_back_lank.php">http://scienceblogs.com/tetrapodzoology/2008/09/come_back_lank.php</a>Carlos Miguel Albuquerquehttp://www.blogger.com/profile/15403916224472065107noreply@blogger.com0tag:blogger.com,1999:blog-4258912848402466459.post-85897121972036730342009-03-07T02:38:00.000-08:002009-03-07T02:58:13.782-08:00Why pterosaurs weren't replaced by birds<strong>Copyrighted</strong> from Richard Butler, Paul Barrett, Steven Nowbath & Paul Upchurch: "Estimating the effects of the rock record on pterosaur diversity patterns: implications forhypotheses of bird/pterosaur competitive replacement, SVP meeting abstracts2008, 59A":<br /><br /><em>"Pterosaurs formed an important component of terrestrial and marginal marine ecosystems during the Mesozoic, and were the first flying vertebrates. The fossil record appears to indicate a decline in pterosaur taxic diversity [ =species count] in the Late Cretaceous, followed by extinction at theCretaceous/Paleogene boundary. This reduction in species-richness has beenlinked to the ecological radiation of birds in the Early Cretaceous -- it has been proposed that early birds competitively excluded pterosaurs from many key niches. Hypotheses of competitive replacement are frequently posited based on the fossil record, but few have been tested in detail. Here we present a detailed examination of pterosaur diversity through time based upon a new comprehensive database of the spatial and temporal distribution of pterosaurs. We use this database to calculate taxic and phylogenetically corrected diversity estimates, and compare these estimates with a model describing temporal variation in rock availability. We use numbers of pterosaur-bearing formations (PBFs) as a proxy for rock availability;temporal variation in the number of PBFs is then used to generate a model in which rock availability is a perfect predictor of diversity. Both taxic and phylogenetic diversity curves are strongly correlated with numbers of PBFs, suggesting that a significant part of the signal contained within pterosaur diversity patterns may be controlled by geological and taphonomic megabiases rather than macroevolutionary processes. Moreover, significant differences between observed diversity and the diversity predicted by the rock availability model coincide with the occurrence of sites of exceptional preservation (Lagerstätten), again indicating major biases in the pterosaur fossil record. There is no evidence for a long-term decline in pterosaur diversity during the Cretaceous, although a reduction in species-richness might have occurred in the Late Cretaceous. Available data provide little support for the long-term competitive replacement of pterosaurs by birds."</em>Carlos Miguel Albuquerquehttp://www.blogger.com/profile/15403916224472065107noreply@blogger.com0tag:blogger.com,1999:blog-4258912848402466459.post-11668931550584596002009-03-01T03:07:00.000-08:002009-03-01T03:59:59.288-08:00Niche map for WIW part 2Note: I've replaced the "Filter Feeder" and "Diver" niches with "Waterbird" and "Fishing mammal", for accuracy reasons.<br /><br /><span style="font-size:180%;">Asia</span><br /><br /><strong>Tall Browser</strong>: Sauropod, Therizinosaur<br /><strong>Low Browser</strong>: Hadrosaur, Ceratopsid<br /><strong>Large Grazer</strong>: Sauropod/Ankylosaur, Hadrosaur<br /><strong>Medium Grazer</strong>: Hadrosaur, Therizinosaur, Pseudoungulate<br /><strong>Small Grazer</strong>: Bipedal Ornithopod, Pseudoungulate<br /><strong>Aquatic Herbivore</strong>: Ceratopsid, Afrothere, Multituberculate, Herbivorous Crocodillian*<br /><strong>Large Omnivore</strong>: Ornithomimid*/Troodontid, Oviraptor, Ceratopsid<br /><strong>Small Omnivore</strong>: Afrothere, Pseudoungulate, Glire, Galliforme/Paleognath/Oviraptor<br /><strong>Large Insectivore</strong>: Afrothere, Alvarezsaurid, Specialized Troodontid/Unenlagiine/Noasaur/Therizinosaur (see below)<br /><strong>Small Insectivore</strong>: Afrothere, Metatherian, Cimolestan<br /><strong>Top Predator</strong>: Abeliosaur/Noasaur, Tyrannosaur<br /><strong>Medium Predator</strong>: Tyrannosaur, Dromeosaur, Hyeanodont/Mesonychian/Metatherian, Crocodillian<br /><strong>Small Predator</strong>: Troodontid/Unenlagiine, Hyeanodont/Mesonychian, Crocodillian, Monitor, Metatherian<br /><strong>Aquatic Predator</strong>: Crocodillian, Mosasaur, Plesiosaur<br /><strong>Arboreal Herbivore</strong>: Specialized Primate, Gondwanaviforme, Multituberculate, Arboreal Ornithopod<br /><strong>Arboreal Omnivore/Frugivore</strong>: Primate, Cimolestan, Dromeosaur, Glire, Scadentian, Metatherian<br /><strong>Arboreal Predator</strong>: Hyeanodont/Mesonychian, Dromeosaur, Metatherian<br /><strong>Winged Frugivore/Nectar Feeder</strong>: Volaticothere, Flying Cimolestan/Primate, Galliforme, Apsaraviforme, Enantiornithe<br /><strong>Winged Insectivore</strong>: Enantiornithe/Neornithe*/Apsaraviforme, Anurognathid, Volaticothere<br /><strong>Winged Predator</strong>: Volaticothere, Enantiornithe, Anurognathid*<br /><strong>Winged Scavenger/Terrestrial Stalker</strong>: Pterosaur, Unenlagiine, Pseudodontorn, Paleognath<br /><strong>Waterbird</strong>: Anseriforme, Paleognath, Flamingo/Presbyornid, Grebe/Loon/Similar Bird, Hesperornithe, Pseudodontorn<br /><strong>Diving Mammal</strong>: Cimolestan, Afrothere, Metatherian<br /><strong>Random Oddity</strong>: Panda like Ceratopsid/Therizinosaur, Anteating Therizinosaur<br /><br />*1.An idea I got just now. Probably it will replace the aquatic ceratopsids, or make them water buffalo analogues, while herbivore crocodillians would be hippo analogues<br /> 2.I think I'll replace them by either troodontids or flightless pterosaurs<br /> 3.I don't know if I should have insect/nectar eating neornithes; therefore, I'll only reffer insect/nectar eating birds as "birds"<br /> 4.Another idea I got just now<br /><br /><span style="font-size:180%;">North America</span><br /><br /><strong>Tall Browser</strong>: Therizinosaur, Hadrosaur/Sauropod<br /><strong>Low Browser</strong>: Hadrosaur, Ceratopsid, Meridiungulate<br /><strong>Large Grazer</strong>: Hadrosaur, Therizinosaur, Sauropod/Ankylosaur<br /><strong>Medium Grazer</strong>: Hadrosaur, Therizinosaur, Pseudoungulate<br /><strong>Small Grazer</strong>: Pseudoungulate, Bipedal Ornithopod, Xenarthran/Meridiungulate<br /><strong>Large Omnivore</strong>: Troodontid, Oviraptor, Ceratopsid<br /><strong>Small Omnivore</strong>: Metatherian, Glire, Xenarthran, Galliforme/Oviraptor/Screamer<br /><strong>Insectivore</strong>: Afrothere, Metatherian, Cimolestan, Xenarthran<br /><strong>Top Predator</strong>: Tyrannosaur<br /><strong>Medium Predator</strong>: Tyrannosaur, Dromeosaur, Hyeanodont/Mesonychian, Metatherian<br /><strong>Small Predator</strong>: Troodontid/Unenlagiine, Hyeanodont/Mesonychian, Metatherian<br /><strong>Aquatic Predator</strong>: Plesiosaur, Champsosaur, Crocodillian<br /><strong>Arboreal Omnivore</strong>: Cimolestan, Multituberculate, Glire, Dromeosaur, Metatherian<br /><strong>Arboreal Predator</strong>: Metatherian, Dromeosaur<br /><strong>Winged Omnivore</strong>: Volaticothere, Galliforme, Apsaraviforme, Enantiornithe<br /><strong>Winged Insectivore</strong>: Bird, Anurognathid, Volaticothere<br /><strong>Winged Predator</strong>: Volaticothere, Enantiornithe, Anurognathid<br /><strong>Winged Scavenger/Terrestrial Stalker</strong>: Pterosaur, Paleognath, Unelagiine, Ichthyorniforme<br /><strong>Waterbird</strong>: Anseriforme, Paleognath, Loon/Grebe/Similar bird, Hesperornithe<br /><strong>Diving Mammal</strong>: Cimolestan, Metatherian<br /><strong>Random Oddity</strong>: Can't think offCarlos Miguel Albuquerquehttp://www.blogger.com/profile/15403916224472065107noreply@blogger.com0tag:blogger.com,1999:blog-4258912848402466459.post-11768385248627967302009-02-28T11:10:00.000-08:002009-02-28T12:26:18.407-08:00Niche map for WIW part 1<span style="font-size:180%;">Africa</span><br /><strong></strong><br /><strong>Tall Browser</strong>: Sauropod (savanna), Hadrosaur (rainforest)<br /><strong>Low Browser</strong>: Ceratopsid, Hadrosaur<br /><strong>Large Grazer</strong>: Hadrosaur, Sauropod/Ankylosaur (ankylosaur like sauropods are welcome)<br /><strong>Medium Grazer</strong>: Hadrosaur<br /><strong>Small Grazer</strong>: Bipedal Ornithopod, Pseudoungulate*<br /><strong>Aquatic Herbivore</strong>: Afrothere, Multituberculate, Ceratopsid<br /><strong>Large Omnivore</strong>: Ornithomimid/Troodontid/Flightless Pterosaur, Oviraptor, Ceratopsid<br /><strong>Small Omnivore</strong>: Afrothere, Pseudoungulate, Glire*, Galliforme/Paleognath/Oviraptor*<br /><strong>Large Insectivore</strong>: Afrothere, Alvarezsaurid, Specialized Troodontid/Unenlagiine/Noasaur<br /><strong>Small Insectivore</strong>: Afrothere, Metatherian, Cimolestan<br /><strong>Top Predator</strong>: Abelisaur, Noasaur<br /><strong>Medium Predator</strong>: Tyrannosaur, Dromeosaur, Hyeanodont/Mesonychian*, Crocodillian<br /><strong>Small Predator</strong>: Troodontid/Unenlagiine, Hyeanodont/Mesonychian, Crocodillian, Monitor<br /><strong>Aquatic Predator</strong>: Crocodillian (obviously), Plesiosaur, Mosasaur<br /><strong>Arboreal Herbivore</strong>: Specialized Primate, Gondwanaviforme*, Multituiberculate<br /><strong>Arboreal Omnivore/Frugivore</strong>: Primate, Cimolestan, Dromeosaur*, Glire<br /><strong>Arboreal Predator</strong>: Hyeanodont/Mesonychian, Dromeosaur, Metatherian<br /><strong>Winged Frugivore/Nectar Feeder</strong>: Volaticothere, Flying Cimolestan/Primate, Galliforme*, Apsaraviforme, Enantiornithe<br /><strong>Winged Insectivore</strong>: Enantiornithe/Neornithe/Apsaraviforme, Anurognathid, Volaticothere<br /><strong>Winged Predator</strong>: Volaticothere, Enantiornithe<br /><strong>Winged Scavenger/Terrestrial Stalker</strong>: Pterosaur, Unenlagiine, Pseudodontorn, Paleognath<br /><strong>Filter Feeder</strong>: Anseriforme, Flamingo/Ornithomimid/Presbyornid<br /><strong>Diver</strong>: Hesperornithe, Loon/Grebe/Similar bird*, Pseudodontorn, Cimolestan, Afrothere, Metatherian<br /><strong>Random Oddity</strong>: Therizinosaur<br /><br />*1.I don't know what Pseudoungulates should be, aside from the fact they are Placentals<br /> 2.There are glires, though neither rodents nor lagomorphs, just basal forms like Anagale<br /> 3.The competitors for the fowl niche<br /> 4.Not sure about which should be present<br /> 5.A linage of hoatzin like enantiornithes I once suggested<br /> 6.There are arboreal dromeosaurs, probably Kay's concepts<br /> 7.Like in Spec there are arboreal galliformes everywhere, being WIW's parrots<br /> 8.I haven't decided; loons are as old as penguins and petrels, but if flamingoes are present their closest relatives, grebes, should be present as well.<br /><br /><span style="font-size:180%;">Europe</span><br /><br /><strong>Tall Browser</strong>: Therizinosaur<br /><strong>Low Browser</strong>: Hadrosaur, Ceratopsid, Pseudoungulate<br /><strong>Large Grazer</strong>: Hadrosaur, Therizinosaur<br /><strong>Medium/Small Grazer</strong>: Hadrosaur, Therizinosaur, Pseudoungulate<br /><strong>Aquatic Herbivore</strong>: Ceratopsid, Multituberculate, Afrothere, Anseriforme<br /><strong>Large Omnivore</strong>: Ornithomimid/Troodontid, Oviraptor, Ceratopsid<br /><strong>Small Omnivore</strong>: Afrothere, Pseudoungulate, Glire, Galliforme/Paleognath/Oviraptor<br /><strong>Insectivore</strong>: Afrothere, Metatherian, Cimolestan<br /><strong>Top Predator</strong>: Tyrannosaur, Dromeosaur<br /><strong>Medium Predator</strong>: Tyrannosaur, Dromeosaur, Hyeanodont/Mesonychian/Metatherian<br /><strong>Small Predator</strong>: Troodontid/Unenlagiine, Hyeanodont/Mesonychian, Metatherian<br /><strong>Aquatic Predator</strong>: Plesiosaur<br /><strong>Arboreal Omnivore</strong>: Cimolestan, Multituberculate, Glire, Dromeosaur<br /><strong>Arboreal Predator</strong>: Dromeosaur, Metatherian<br /><strong>Winged Omnivore</strong>: Apsaraviforme, Galliforme, Enantiornithe<br /><strong>Winged Insectivore</strong>: Enantiornithe/Apsaraviforme/Neornithe, Anurognathid, Volaticothere<br /><strong>Winged Predator</strong>: Volaticothere, Enantiornithe<br /><strong>Winged Scavenger/Terrestrial Stalker</strong>: Pseudodontorn, Pterosaur, Unenlagiine, Paleognath<br /><strong>Filter Feeder</strong>: Anseriforme, Flamingo/Ornithomimid/Presbyornid<br /><strong>Diver</strong>: Hesperornithe, Loon/Grebe/Similar Bird, Pseudodontorn, Cimolestan, Metatherian, Afrothere.<br /><strong>Random Oddity</strong>: Arboreal Hyeanodont/Mesonychian, Flying Primate/Cimolestan in the Mediterranean, Sauropod in the same regionCarlos Miguel Albuquerquehttp://www.blogger.com/profile/15403916224472065107noreply@blogger.com0tag:blogger.com,1999:blog-4258912848402466459.post-60130446523110114312009-02-12T03:43:00.000-08:002009-02-12T03:47:15.703-08:00Bitchy MetazoicaIt seems that fat whore that made Metazoica proves her arrognace and ignorance are equal to that of the most motherfucking creationist:<br /><br /><a href="http://metazoica.blogspot.com/">http://metazoica.blogspot.com/</a><br /><br />Don't listen to what that fucking whore says; she clearly is ignorantCarlos Miguel Albuquerquehttp://www.blogger.com/profile/15403916224472065107noreply@blogger.com6tag:blogger.com,1999:blog-4258912848402466459.post-43369140005844360162009-02-07T05:43:00.000-08:002009-02-07T07:39:13.694-08:00Mark Witton vs John ConwayFor those interested in pterosaurs, you might recognise these two artists, which seem to be on the leading positon on the pterosaur imagery/paleobiological speculation business (well, Mark is at least; John seems to have turned off, although he still seems to be alive). The whole purpose of this waste of time its too see which of these wonderfull artists depicts pterosaurs better and thus to see which one is decent/mentally sane/whatever.<br /><br />Anyway, since I haven't asked for the permission of using their pictures, use the following links:<br /><br /><a href="http://www.flickr.com/photos/markwitton/">http://www.flickr.com/photos/markwitton/</a><br /><a href="http://jconway.co.uk/">http://jconway.co.uk/</a><br /><br />And now we shall begin.<br /><br /><strong>Favoured species</strong><br /><strong></strong><br />Mark Witton depicts many different pterosaur species; in fact, there not a single pterosaur group he missed. I still pity the fact that he largely ignored ctenochasmatoids (aside from Pterodactylus & Pterodaustro, he didn't portrayed any other specie, which is a shame, because I really want to know his opinion on Cycnorhamphus and Cearadactylus), and he still rarely does non-pterodactyloid pterosaurs (aside from Dimorphodon). From the number of pictures he did, the pterosaur family he focused the most on was <strong>Azhdarchidae</strong>, and, truth to be told, it was quite predictable; after all, he was one of the two people responsible for showing the world they weren't skimmers but stork-like generalists, right? His first pictures of such animals were somewhat inaccurate (the first depicted them with a neck too thin and hunting in shallow water, the second showed a horrendous skinny thing, with thin wings in addition to the thin neck, and the third shows something akin to his first image but with a neck still too thin and taking off on a bird like fashion), but afterwards his were considered the best depictions of these pterosaurs on the net.<br /><br />John Conway, on the other hand, seems to have a liking on a rival linage of flying reptiles, the <strong>Ornitocheiroids</strong>. His favourite species seem to be Anhanguera, Pteranodon and Nyctosaurus, which represent clades <strong>Ornitocheridae, Pteranodontidae</strong> and <strong>Nyctosauridae</strong> (if the later is distinct of the second, obviously). Other pterosaurs, however, received some attention from him; the ctenochasmatoid Pterodactylus, and the tapejarid Sinopterus (although he seems to regard Sinopterus and Nemicolopterus as distinct, the fact is that the later is a juvenile of the first, so...), however, still received some attention from him.<br /><br /><strong>Pterosaur wing designs</strong><br /><br />Mark depicts pterosaurs with their patagium connecting to their legs/feet. This view, often considered quite old and unoriginal (after all, bats too have their wing membranes like that), might actually be very accurate, because evidence shows that many pterosaurs had their wing membranes connecting to their legs/feet, and quite possibly all pterosaurs were like this. The propatagium is well shown in his earlier pictures, with the pteroid rised and shown to be supporting two membranes: one between it and the shoulder and the other between it and the hand. Nowdays, though, his flying reptiles seem to have a smaller and more typical pteroid, with no membrane connecting it to the hand, thus having a single, more "traditional" propatagium. The uropatagium in his pterosaurs is quite big in basal species, to the point that it even connects the two legs, but that excludes the tail. In pterodactyloids, it is reduced to two small membranes running along both legs, which, according to him, is one of the reasons advanced pterosaurs had a better ground locomotion than their ancestors.<br /><br />In John's pterosaurs, the wing structure is quite different. He depicts his pterosaurs with the wing membranes connecting to the hips, giving their wings a more avian shape. At the most they connect to the knees, but no further. The propatagium is pretty much as in birds; the pteroid is hardly visible, and he seems to think it might be able to inflate, like the ones of pelicans and some other birds. His uropatagium is composed of two distinct membranes running along the legs as in Mark's, but they are much more developed and almost make the back limbs resemble the tail feathers of birds like kites and frigate birds, and they could have had the same function. The feet are also webbed, further stressing the role of the feet in steering. The actinofibrils seem also to be more visble in his pterosaurs, making their wings more similar to those of birds.<br /><br /><strong>Lifestyle depictions/implications</strong><br /><br />Mark presents a vivid alternative to the steryotypical view that pterosaurs are sea bird analogues. Based on actual evidence overlooked by nearly everyone else, he managed to show the possible real lifestyles of many pterosaur species. For instance, rather than fish eaters, his tapejarids are galliforme analogues, running or climbing in search of animal and plant matter (though his first picture of this group depicts a sea bird like animal, and the second a falcon like predator; however, at the time he wasn't as wise as he is now). Dimorphodon passed from a puffin like fish eater to a tree climbing predator, and, as we all know, azhdarchids are now seen as terrestrial thanks to him. The wings of his pterosaurs also reflect their lifestyles; terrestrial forms have shorter, broader wings, while his ornitocheiroids, while still having their membranes attaching to the legs, have much longer wings, thus resulting on a thinner wing shape. Overall, his pterosaurs are as diverse as our birds.<br /><br />John Conway, on the other hand, offers a more limitated view on pterosaur ecology. Aside from Germanodactylus (portrayed as a small opurtonist), Pterodactylus (portrayed as a shore bird like prober) and Nemicolopterus (depicted as a robin like omnivore), and possibly Zhejiangopterus (seen on the ground, though no particular lifestyle is atributed to it), all of his pterosaurs seem to be sea bird analogues, using their thin wings to soar over coasts or seascapes. His Quetzalcoatlus, seen flying over a lake and with a neck quite shorter than Mark's, seems to be a skimmer (though its size seems to suggest that its a baby, not a full grown pterosaur), and his Sinopterus is implied to be a seagull or skimmer like form.<br /><br /><strong>Conclusion</strong><br /><br />As a whole, I prefer Mark Witton. While John Conway has beutifull pictures, they are overall wrong in the anatomy and lifestyle of pterosaurs. Though they are too beutifull to go to waste, and certainly original, depicting pterosaurs as more bird like than bat like, they sadly lack the accuracy of Mark's works. I wish he uploads something new soon though; I'll ignore the wing membranes (as I always do; they look better in the way he depicts them anyway) as long as he shows pterosaurs that aren't sea bird like.Carlos Miguel Albuquerquehttp://www.blogger.com/profile/15403916224472065107noreply@blogger.com0tag:blogger.com,1999:blog-4258912848402466459.post-48992693692564265432009-01-04T11:42:00.000-08:002009-01-04T12:53:20.337-08:00The Katurran Journey: The good, the bad and the ugly<strong>The Katurran Odyssey</strong>, as you may agree, is a beutifull book. Created by the Star War designer <strong>Terryl Whitlacth</strong> and the screenwriter <strong>David Michael Wieger, </strong>certainly this is a master piece in many aspects. The ilustrations are simply amazing and breath taking; both the landscapes, the seascapes, and above all the characters, are beutifully ilustrated; I specifically enjoyed the bats, birds and pterosaurs flying in a the brightly coloured sky. The main character, Katook the lemur, is as cute as a real lemur (his blue eyes make him very beutifull as well, but still I prefer the brown eyed primates), and Quigga is better than all quagga pictures I've seen; I'm now ashamed for having never seen one alive (no one nowdays can anyway). The sea is beutifully decorated in a scene by beutifull fish, cetaceans and icthyosaurs, and Gamic's spectral appearence strongly reminds me of an aye-aye (oh wait, he's an aye-aye). The bone crushers (if they are hyenas, hyenodonts or mesonychians, I have no idea) and the other predators have that charm only real carnivores have, and the golden monkey city strongly is superior in terms of beuty to even the Indian temples or the mayan pyramids. Indeed, everything is beutifull.<br /><br />However, everything beutifull has its dark side, and The Katurran Odyssey is no exception. Beneath these layers of magnificience lay sublimal messages that are simply horrible to me, and yet very obvious (otherwise I wouldn't be wasting my time writing this crap). Thats why I actually have to sadly compare this book with a series that I, and many other sane people, hate: The Chronicles of Narnia.<br /><br />Perhaps the most obvious message this book transmits is religion. The story has a particular character that makes obvious what I'm saying. The Fossah (note: mispelling of the word "Fossa", though the word is spelled somewhat like that, in english obviously [I won't involve portuguese because I know english speakers can't pronounce portuguese words correctly]) is obviously the author's answer to C.S. Lewis Aslan: he seems to be (no, he IS) an alegory for Jesus (and he's a feliforme mammal, thus making the connections even more obvious, though I can't accuse the jerks of copyrighting), or at least of the christian God (whereas Jesus and God are supposed to be one and the same I have no fuckin' idea; thats why I'm not christian, as I don't believe in things that contradict themselves!). After all, he is a supernatural figure who is also supposedly the creator of Katurran's world, and most importantly he was also alongside Katook during the whole story and is worshipped by at least the lemurs. Not to mention the fact that he also has his "angels", the swifts and the butterflies. And a heaven like place.<br /><br />The problem is not the fact this book promotes religion (in fact, I don't mind to read christian literature as long as there's tolerance towards other beliefs), but it also promotes aspects of religion that are morally dangerous. I hope the authors did this as an accident, otherwise they need to explain me a lot of things.<br /><br />The first is creationism. There's not a single non-avian dinosaur in the whole movie (which lead a critic to say that they show other "prehistoric stars"; check this book's site), but many other prehistoric animals appear, from the Mesozoic Archeopteryx, icthyosaurs and pterosaurs to the Cenezoic mammoths, terror birds, Osteodontornis (a sea bird), Zeuglodon (a primitive whale) and Thylacosmilus (a saber toothed marsupial), as well as the recently extinct thylacine and quagga. All these creatures are seen side-by-side with modern animals (most of them endangered), so its hard to believe a shade of creationism prommotion is absent. I don't need to say why creationism is bad, and if you don't know just contact me and I'll tell ya.<br /><br />The other is racism and/or specieism (and religious intolerance; keep readin'). Like in many christian fantasy series (Narnia, Lord of the Rings, Harry Potter [yep, J.K. Rowling is christian], etc.), the villains belong to a specific specie, instead of having antagonists of the same species of the heros. The golden monkeys are an obvious example, and being endangered as they are it would give them a bad image, thus proving fatal for their conservation. Even more outrageous is having the evil priest Gamic as an aye-aye, already in trouble because of religious practises in Madagascar of killing any aye-aye that appears in front of a person. The fact the golden monkeys worship themselves is also an attack to LaVeyan Satanism, and showing the Koloboos as wise but cold is almost like saying "if you are smart then you are evil!"<br /><br />Thus, while its a beutifull work of art, it certainly its an imoral book<br /><br />(Yes, I know I got the title wrong; however, while I left the post's title alone, I corrected the title in the message)Carlos Miguel Albuquerquehttp://www.blogger.com/profile/15403916224472065107noreply@blogger.com0tag:blogger.com,1999:blog-4258912848402466459.post-73277112509010281202009-01-02T02:55:00.000-08:002009-01-02T03:47:40.072-08:00Opinions on non-Galliforme/Anseriforme GalloanseraeProviding the fact toothed seabirds took most of Spec's seabird niches, I had to change the pseudodontorns from gannet/albatross/pelican analogues into Spec's mergansers. I've also decided to express my opinion on Gastorniformes and on dromornids<br />-------------------------------------------------------------------------------------------------<br /><br />Galloanserae is an old linage of Neornithe birds, which has included, across the history of both worlds, both fowl and waterfowl; both groups are actually on the opposite sides of the cladistic tree, since Galliformes are the most basal and Anseriformes are within a larger clade that also included at least two other groups (though one of these groups might belong within Anseriformes; see below). Both groups are still alive in Spec, though neither developed the spectacular forms present on HE.<br /><br />One of these groups is Gastorniformes. On HE, they develop spectacular forms such as Gastornis, flightless and huge; their huge bills might had been used to crush their prey, though its not clear if they were carnivores (though its more likely they ate meat than their aussie relatives, the dromornids). On Spec, this clade is alive and well in South America (its interesting to note that, on HE, there was another giant, flightless relative of waterfowl known as Brontornis, though it wasn't a Gastorniforme [unless the features that unite them to Drmornidae and Anseriformes are resulted from parallel evolution]), where they took the niches of Galliformes. They are quite similar to HE's screamers, which are true Anseriformes, and which never evolved in Spec (though their closest relatives, magpie geese, occur in Australasia, and gave rise to the huge flightless "geese" in New Zealand). A similar niche is occupied in Oz by very similar birds, though they might be dromornids; in both landmasses there's arboreal Galliformes as well.<br /><br />Pseudodontorns are the other group of Galloanseres that got extinct on HE; in Spec, they still exist, though they never developed the albatross like forms that evolved on our timeline. These ncihes were taken by Ichthyorniformes, which took over most seabird niches but those of large diving birds (those are held by Hesperorniformes and penguins). Instead, these actually occupy a somewhat marginal niche, but still interesting to note because they managed to prevent Anseriformes from taking it: that of mergansers. On HE there's at least 4 linages of diving freshwater birds, and Spec has 3. Mergansodontorns have their earliest fossils dating from the Eocene, though its possible their origins extend to the Cretaceous, since Pseudodontorns weren't very specialized at that timeCarlos Miguel Albuquerquehttp://www.blogger.com/profile/15403916224472065107noreply@blogger.com0tag:blogger.com,1999:blog-4258912848402466459.post-74485552701358159312008-12-07T01:05:00.000-08:002008-12-07T07:28:08.786-08:00PseudodontornsAt last...<br />-------------------------------------------------------------------------------------------<br /><br />Euornithes, as a whole, have been masters at colonising the seabird niches; since the Cretaceous there's basal toothed seabirds like the ichthyorniformes and the hesperorniformes, and both groups are still very common on Spec, having taken the niches of seagulls, terns, skimmers, auks, flamingoes, vultures (a linage of ichthyorniformes abandoned the sea and became scavengers), cormorants, darters and penguins (in the northern hemisphere obviously). Neornithes also produced their own handfull of seabird species; petrels and tropicbirds cruise Spec's skies, shorebird like paleognaths gather in the coast lines, and penguins rule supreme over the southern oceans. However, there's another linage of seabirds that occur in Spec, and which gave rise to the biggest flying birds [aside from the rocs?] that occur in this world.<br /><br />Perhaps interesting to note is the fact that there's no gannets nor pelicans in Spec, and its albatrosses are reduced to a few species from the south, often refered as "p-Phobetria". Instead, the pseudodontorns, or "false-toothed birds", rule over the large seabird niches.<br /><br />Pseudodontorns, unlike most marine neornithes, do not belong the "waterbird clade", nor are they p-Charadriiformes (which too never evolved on Spec), but rather they are actually relatives of waterfowl and fowl, and thus they must have diverged from them already in the Cretaceous, when Galloanserae was already well defined. At this time, the ornithocheiroid pterosaurs ruled over large "seabird" niches, but towards the Eocene most of them disappeared, with modern species living as relics here and there. This left a vacuum to be filled, and ichthyorniforme seabirds took advantage, giving rise to big forms; however, towards the Miocene, they started to decline, and so pseudodontorns occupied the niche.<br /><br />As the name suggests, these birds don't have true teeth (lost forever by the first neornithes, though genetic manipulation does cause pseudodontorns to grow actual teeth), but teeth-like serrations in the bill, which are used to grab prey like ammonites, small/baby baleen squids and fish. Pseudodontorns, like most seabirds (and unlike Anseriformes and Galliformes), have nidiculous chicks, which need parental care for a shorter period of time than other seabirds, up to a month and a half in the bigger species.<br /><br /><strong>Pelagornithidae</strong><br /><br />The "typical" pseudodontorns, they are mostly gannet, booby and albatross like forms<br /><br /><strong>North Atlantic Grannet</strong> (<em>Odontomorus bassanus</em>)<br /><br />Grannet colonies are a typical sight in the North Atlantic. Fairly larger than their HE analogues, they have wingspans of up to 3 meters; some individuals are reported to reach wingspans of up to 3.7 meters. One of the largest flying seabirds of the northern hemishere, they dive in the manner of HE's gannets, and then swim after their prey underwater like them; in fact, <em>Ondontomorus</em> is the pseudodontorn genus with the shorter and stronger wings. Its still a good fliers though, spending most of its time soaring above the sea in the manner of other pseudodontorns. Unlike HE's gannets, Spec's grannets are slightly more diverse, with three Pacific species in addition to the two Atlantic ones.<br /><br /><strong>Spectacled Hobbie</strong> (<em>Adamastosula pelagica</em>)<br /><br />A quite common specie of hobbie, this bird occurs in the Pacific ocean (sometimes, its range overlaps with the Northen Pacific Grannet, <em>Odontomorus sednai</em>), with breeding colonies in islands such as the Galapagos and Hawaii (it shares its range with more restricted hobbie species, like the Galapagos Hobbie, <em>Adamastosula darwinensis</em>, and the Aloha Hobbie, <em>Adamastosula maui</em>). Its name is derived from the white markings around its eyes (its head is black), which roughly resemble glasses. This bird, a typical sized hobbie (roughly the same size of a grannet, though with a longer wingspan, up to 4 meters) is, as the name suggests, more pelagic than its relatives, which allows it to have a larger distribution across the Pacific. Like all hobbies, its dives from the air in order to capture its prey.<br /><br /><strong>Azorian Lollymawk</strong> (<em>Pelagoptera callisto</em>)<br /><br />A common sight in the Atlantic ocean, this middle sized pseudodontorn (with a wingspan of 4.5-5.3 meters) is a typical "albatross-like" pelagornithid, soaring above the waves feeding on fish and cephalopods from the water surface, rather than diving. It also feeds on the carcasses of dead balleen squids, walducks or mosarks; being the largest seabird on the North Atlantic, it has no problems driving off smaller scavengers.<br /><br /><strong>Wandering Pseudotross</strong> (<em>Odontodiomedea exulans</em>)<br /><br />The largest living flying bird, this creature's wingspan rivals with that of Pteranodon, reaching 8 meters in length. Basically a monstrously huge version of HE's wandering albatross, this magnificient bird is as tall as a man, so most specsplorers don't dare to come very close to their nesting sites in the Austral ocean islands; Kerguelen, in particular, is a well known site. They occur in the southern seas, but occasional speciemens have been reported as north as the Galapagos. Like most pelagornithids, these birds form "life-long" bounds, though they can "divorce" if they fail to have healthy chicks too many times.<br /><br /><strong>Njordornidae</strong><br /><br />The "odd pseudodontorns", they consist of two genera (plus some fossil ones, which closely resemble modern forms) that took over the pelican and skua niches. Unlike pelagornithids, these birds, which are more coastoal, have broader wings like those of avisaurs and rocs, as they use thermals to fly, rather than just oceanic winds.<br /><br /><strong>Aussie Pelitooth</strong> (<em>Ododontopelicanus antipoda</em>)<br /><br />The pelicans of Spec, pelitooths only have tooth like serrations in the upper jaw, while the lower one has the obvious pouch used to catch and carry the prey. While occuring in the same areas as HE's australian pelican, the aussie pelitooth actually resembles more HE's brown pelican, though obviously larger, with a wingspan of about 4 meters. Pelitooths, unlike pelagornithids, don't form permanent male/female couples; they usually chase after females in male/male couples, like HE's pelicans. Though, unlike them, both males raise the chicks, and so the female can mate with other males and thus have a higher chance of her genes to be transmitted to the next generation.<br /><br /><strong>Hākoakoa </strong>(<em>Njordornis australis</em>)<br /><br />With a wingspan of 3 meters, this bird is Spec's Brown Skua, occuring in Antartic and Sub-Antartic environments. Its beak serrations and size make few penguins safe; only the very big teals, and the deadly penguins of death, can safely ignore this aerial killers (the latter, though, have a taste for hākoakoan flesh). Like pelagornids, they form monogamous pairs, though they usually only last a season.Carlos Miguel Albuquerquehttp://www.blogger.com/profile/15403916224472065107noreply@blogger.com0tag:blogger.com,1999:blog-4258912848402466459.post-35464811291444585812008-12-03T10:12:00.001-08:002008-12-03T12:34:18.686-08:00Extinct XenornithesThis a [horrible] essay about extinct xenornithes.<br /><br />------------------------------------------------------------------------------------------<br /><br /><br /><br />Modern xenornithes are all classified in two orders: Xenorniformes (bunglebirds and nerds-of-paradise), and Pithecaviformes (carpos and paradise carpos). The origins of this group seem to steam from early Cretaceous †Confuciusornidae, which are very similar to modern bunglebirds; for about 65 million years, however, there was a huge gap in Xenornithe fossil record, though at least two jaws from the Maastrichian and some fragmentary remains from the Paleocene might belong to early Xenornithes. What is clear, though, is that violently reappear in the Eocene; in a space of merely 50,000 years, the Xenornithe fossil record passes from a few near fragmentary remains to thousands of nearly complete (and complete) skeletons; Messel was the site that revealed the larger quantity of Xenornithes so far. Because of the large diversity of Eocene Xenornithes, it very often assumed that the forerunners of the known clades made their first appearence in the late Cretaceous or at least in the Paleocene, but right after the thermal maximum there was literally an explosion on these birds' diversity. Such event is blamed on the effects of the thermal maximum: the expansion of the tropical rainforests, as well as a decline in Enantiornithe diversity (all post-Cretaceous opposite-birds trace their origin to merely 6 different ancestors from the Maastrichian; probably 5 or even 4, if the tweetie birds and specworld finches and parrots turn out as sister taxa, or if that such thing happens with ebergs and euavisaurs, which seem to have diverged from a single seagull/shorebird like ancestor) seemed to have been responsible for the "Eocene Explosion".<br /><br /><br /><br />Modern Xenornithes, as obvious, made their first appearence in this epoch; the earliest bunglebird, †Eoxenavis, was already present, and the distinction between carpos and paradise carpos had already been made at the Eocene. Some extinct Xenornithes were indeed very closely related to modern carpos.<br /><br /><br /><br /><strong>"Confuciusorniformes"</strong><br /><br /><br /><br />Many of the Eocene's Xenornithes are very similar to the Cretaceous Confuciusornids. Many Eocene "Confuciusornids" are often mistaken for early bunglebirds, and might in fact belong to Xenorniformes. Such genera include <em>Aristotelornis</em>, <em>Awen</em> and <em>Messelavis.</em><br /><br /><strong></strong><br /><br /><strong>Thanatiformes</strong><br /><br /><strong></strong><br /><br />Perhaps the most notable of Spec's Xenornithes, dead or alive, these birds are classified in two families, Thanatids and Tyrannavids. As the crown genus' name, <em>Thanatos</em> (literally "death" in latin), suggests, these birds are assumed to be predatory: their feet strongly resemble those of euavisaurs and those of HE's Falconiformes and Acciptriformes, and they also possess hooked beaks, sometimes with teeth-like serrations akin to those of HE's falcons. Because of their ear asymmetry, they are thought to had been nocturnal, leaving the diurnal predator niches to the first euavisaurs. Their disappearence is consistent with the disappearence of the global forests and the appearence of the first scowls, all in the beginning of the Neogene.<br /><br /><br /><br /><em>Thanatos</em><br /><br /><br /><br />Known mainly from Europe and North America sites, some other thanatid taxa might be synonymous with it. It life, this falcon sized bird would had resembled HE's strigid owls (only with wing claws and a non-zydactyl feet), though more accurate reconstructions depict it with the facial disc of feathers in the head, which Thanatiformes appearently lacked. It has also well defined canine-like serrations on the beak. Three species are known, though only <em>T. adamaste</em> has been well described.<br /><br /><br /><br /><em>Xenotyto</em><br /><br /><br /><br />A close relative of <em>Thanatos</em>, this bird is known mainly from North America and Europe, with fossils in South America as well. It has longer legs than its european relative, probably hinting towards a cursorial lifestyle akin to that of HE's borrowing owls, though it was more likely like HE's barn owls.<br /><br /><br /><br /><em>Falcostrigyx</em><br /><br /><br /><br />Possibly a synonym of <em>Thanatos</em>, it is mainly known from Mongolia. It is almost identical to its european relative, though it lacks the canine-like serrations. Some yet to be described australian forms might belong to this genus, if it is valid.<br /><br /><br /><br /><em>Enantiophagus</em><br /><br /><br /><br />Known exclusively from South America, it differs from other thanatids in the way it might have had a feathered facial disc like HE's owls and Spec's jungle demon. Its name (literally "opposite eater") is a refference to fossiliazed baby enantiornithes (appearently early specworld finches) found in one specimen's stomach; presumably it died before regurgitating the prey's bones in a pellet, as other thanatiformes are known to had done (we have fossil pellets).<br /><br /><em>Tyrannavis piscivora</em><br /><br />The single specie of a single genus of a single family (all other thanatiformes belong to Thanatidae), this bird differs from its closest relatives due to the absence of the typical ear asymmetry (which suggests that it might had been diurnal), and due to its longer, more powerfull beak; in life, it would had been like a HE's osprey with wing claws. It seems to had been a fish eater, as fish scales were found on its stomach.<br /><br /><strong>Enarorniformes</strong><br /><br />This clade only includes, as far as it is known, only two genera: <em>Enarornis</em> and <em>Pekkalavis</em>. The first fossil uncovered (a metatarsus) came from Finland ("Enare" means lake in sweedish, and this very first fossil was found roughly 2 miles south of lake Inari), though since then more complete remains came from other parts of Eurasia and North America. Both species are turkey sized (<em>Pekkalavis</em> mainly differs from having a hooked beak and a smaller hallux digit in the feet), have big, round wings, and gastroliths in the stomach; it has therefore been asumed that they occupied a niche roughly similar to the Early Cretaceous <em>Omnivoropteryx</em> and <em>Sapeornis</em> (which are unrelated to Xenornithes), as soaring omnivores.<br /><br /><strong>Pithecaviformes</strong><br /><br />While obviously not extinct, carpos have some extinct relatives.<br /><br /><em>Germanocarpo</em><br /><br />A crow sized Pithecaviforme from Europe, this bird resembles the earliest known carpo, <em>Paleocarpo</em>, though it is still capable of flight; however, it is phylogenetically the most basal known Pithecaviforme (and perhaps the oldest, since fragmentary remains from the late Paleocene might belong to this genus; certainly, the possible xenorthitian owners of the parrot like jaws from the late Cretaceous are related to it). Because it already had a quite parrot like beak, it seems that the less powerfull beak of the paradise carpos isn't an ancestral characteristic of this clade.<br /><br /><em>Hesperoxenornis</em><br /><br />Probably a synonym of <em>Germanocarpo</em>. Known from the Americas.<br /><br /><em>Parsidiocarpopteryx</em><br /><br />An early genus of paradise carpos, appearently still able to fly (though modern paradise carpos might had lost their ability to fly multiple times, as opposed to the true carpos, already flightless in the Eocene); fossils occur in Eurasia and North Africa, thus showing that paradise carpos weren't always restricted to Africa (some undescribed fossils also came from South America).Carlos Miguel Albuquerquehttp://www.blogger.com/profile/15403916224472065107noreply@blogger.com0tag:blogger.com,1999:blog-4258912848402466459.post-69222252597467719092008-11-29T13:42:00.000-08:002008-11-29T15:30:51.038-08:00Pterosaurs for Spec (part 2)Part 1 is in my old <a href="http://reviewsandessays.blogspot.com/">blog</a><br /><br />-----------------------------------------------------------------------------------------------<br /><br /><strong>Demon Terrorsaur</strong> (<em>Deinoapterosaurus robusta</em>)<br /><em></em><br />When the first sightings of this poorly understood beast occured, it was belived to be an aberrant carnocursorid that somehow got stuck on Sulawesi. However, when the first actual specimen was shot...er, "collected", specologists saw not a flightless azhdarchid, but something completly different and more interesting. Unlike the other flightless predatory pterosaurs, which are elegant, cursorial beasts with a hooked but toothless beaks, the demon terrorsaur truly deserves its name: it has a long snout armed with long, stabbing teeth; it is also ill suited for long term runnings, and as such it is an ambush predator, with short but powerfull legs that end in long clawed toes. With the size of a lion, it feeds on the several ornithopod species that live on its range, but doesn't hesitate to rip an explorer apart.<br /><br />Its exact evolutionary relationships are unknown; genetic data seem to suggest that it diverged from other pterodactyloids in the late Jurassic, and it might be related to the ornithocheiroids. Fossils of appearent relatives of this creature showed up in Riversleigh; these possible ancestors are already suited for a terrestrial lifestyle, but still capable of flight. Nowdays, the wing finger was turned into a spur; its exact function is unknown.<br /><br /><span style="font-size:130%;">Azdarchoidea</span><br /><br />The most diverse clade of living pterodactyloids, it includes the azhdarchids, the carnocursorids and one oddball species.<br /><br /><strong>Tezcatlipoca</strong> (<em>Aztecoptera sauroselenidera</em>)<br /><br />A close relative of azhdarchids, this pterosaur resembles the tapejarids, specially Sinopterus from Cretaceous China. It occupies a similar niche to that of the african and asian olitiaus, soaring above the canopy in search of fruits; its size, though small for a pterosaur (4 meter wingspan), its still to big for it to venture into the denser lower layers of the forest, leaving them to frugivore birds; exceptions occur, of course, in clearings on the forest, usually produced by pachamacs. Juveniles are mainly invertebrate eaters, and adults sometimes do kill birds and specworld bats.<br /><br /><span style="font-size:130%;">Azhdarchidae</span><br /><span style="font-size:130%;"></span><br />A somewhat paraphyletic family, it was already present in the Cretaceous as forms like Quetzalcoatlus; by the Paleocene, they developed frugivore forms, and by the Oligocene, some returned to their grassland niches.<br /><br /><strong>Fell Beast</strong> (<em>Tolkienopteryx giganteus</em>)<br /><br />This pterosaur, the biggest modern flying one (as big as Quetzalcoatlus), occurs in the Americas. Big and with a bald head, the adults occupy a niche akin to that of HE's now extinct teratorns, feeding on both carrion and small animals. Juveniles often fly around adults, attacking viciously, alongside mistriders, swoops and juvenile avisaurs, the insects scared by the bigger pterosaurs.<br /><br /><strong>Toth</strong> (<em>Threskiosaurus theornis</em>)<br /><br />Ocurring in Eurasia, Madagascar and Africa, this pterosaur is brightly coloured; its pink fur colour probably derives from aquatic molluscs that consist up to 30% of its diet; this pterosaur prefers wetter environments than other azhdarchids. The juveniles of this specie, avid insect eaters, rest in huge flocks in the river banks, like HE's bee-catchers.<br /><br /><strong>Australian Batard</strong> (<em>Neoazhdarcho ophidophagus</em>)<br /><br />Living in Australia and New Guinea, occuring as a vagrant in New Caledonia and New Zealand, this pterosaur doesn't seem to be particularly closely related to the flightless pterosaurs that live in this area; it seems to have arrived from Asia in the Pliocene. As its scientific name suggests, it is quite notorious for attacking snakes, in a style akin to the St. George's Skreet and HE's secretary bird, by kicking the lepidosaur with its clawed feet.<br /><br /><strong>Roc</strong> (<em>Roc terriblis</em>)<br /><br />Occuring all over Eurasia and Africa, this is the pterosaur analogue to HE's vultures and to Spec's harpies and vulgures. It has a powerfull hooked beak like that of carnocursorids, though it evolved independently.<br /><br /><strong>Dudu</strong> (<em>Apterazdarcho neocaledonensis</em>)<br /><br />This flightless pterosaur resembles the flying azhdarchids, except that it lost the wing membranes (aside from a small flap of skin supported by the reduced wing finger, which replaced the now absent head crest as the main display organ). Incapable of flying, this creature literally eats everything that its beak allows, from small insects and lizards to fruit, carrion and even rath eggs; it occupies a niche roughly similar to that of a vulgure or a gluck. As soon as they born the flaplings climb to the trees like komodo dragons do in our world, in order to avoid the ravenous apetite of the adults; they are able to glide, as the wing membrane at this life stage is still quite big; only as they grow it becomes smaller, thus allowing them to have a fully terrestrial lifestyle.<br /><br /><span style="font-size:130%;">Carnocursoridae</span><br /><br />In the Oligocene/Miocene boundary, Australia has lost all of its vertebrates larger than a dog. Such mass extinction seems to had been caused by an asteroid, though there is evidence of a long term decline of Australia's theropods before the extraterrestrial blow; in fact, right before the collision, the remaining theropods were all maniraptors (I'll later write an essay about that). In any case, Australia was devoid of predators by the Miocene; the only remaining theropods, alvarezsaurids, were too specialized into eating insects like ants and termites. Afterwards, cedunosaurs came from Asia, but it was already after Australia gained its new top predators, the first to challenge the theropod supremacy since the Triassic (if we ignore the large land crocs that evolved in the mean time). One of this groups steamed from ornithopoda: the saber-toothed rhyncoraptors. The other was derived from the azhdarchids that recolonised Australia after the bolide, which gave rise to the carnocursorids, or "terrorsaurs" (though unrelated to the already mentioned Jungle Terrosaur). In order to full fill this niche, they completly lost their wings, while their beaks became hooked like that of the roc. Historically they developed omniviorous forms akin to HE's dromornids and Spec's gobblers, though modern species are all carnivores.<br /><br />(I think I'll leave individual species for you guys to decide)Carlos Miguel Albuquerquehttp://www.blogger.com/profile/15403916224472065107noreply@blogger.com0tag:blogger.com,1999:blog-4258912848402466459.post-32211171989849283952008-11-29T01:51:00.001-08:002008-11-29T01:53:25.514-08:00New blogI decided to make a new blog. Due to password problemsCarlos Miguel Albuquerquehttp://www.blogger.com/profile/15403916224472065107noreply@blogger.com0