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.
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.
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.
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.
The "typical" pseudodontorns, they are mostly gannet, booby and albatross like forms
North Atlantic Grannet (Odontomorus bassanus)
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, Ondontomorus 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.
Spectacled Hobbie (Adamastosula pelagica)
A quite common specie of hobbie, this bird occurs in the Pacific ocean (sometimes, its range overlaps with the Northen Pacific Grannet, Odontomorus sednai), with breeding colonies in islands such as the Galapagos and Hawaii (it shares its range with more restricted hobbie species, like the Galapagos Hobbie, Adamastosula darwinensis, and the Aloha Hobbie, Adamastosula maui). 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.
Azorian Lollymawk (Pelagoptera callisto)
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.
Wandering Pseudotross (Odontodiomedea exulans)
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.
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.
Aussie Pelitooth (Ododontopelicanus antipoda)
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.
Hākoakoa (Njordornis australis)
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.