|
Hesperornithidae
Hesperornithes is an extinct and highly specialized group of aquatic avialans closely related to the ancestors of modern birds. They inhabited both marine and freshwater habitats in the Northern Hemisphere, and include genera such as '' Hesperornis'', '' Parahesperornis'', '' Baptornis'', '' Enaliornis'', and '' Potamornis'', all strong-swimming, predatory divers. Many of the species most specialized for swimming were completely flightless. The largest known hesperornithean, '' Canadaga arctica'', may have reached a maximum adult length of . Hesperornitheans were the only Mesozoic avialans known to colonize the oceans. They were wiped out in the Cretaceous–Paleogene extinction event, along with enantiornitheans and all other non-avian dinosaurs. Anatomy and ecology Most of what is known about this group rests on analyses of single species, as few provide sufficiently complete fossils for analysis. Although some of the smaller and more basal species, like those belonging to ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hesperornis BW (white Background)
''Hesperornis'' (meaning "western bird") is a genus of cormorant-like Ornithuran that spanned throughout the Campanian age, and possibly even up to the early Maastrichtian age, of the Late Cretaceous period. One of the lesser-known discoveries of the paleontologist O. C. Marsh in the late 19th century Bone Wars, it was an early find in the history of avian paleontology. Locations for ''Hesperornis'' fossils include the Late Cretaceous marine limestones from Kansas and the marine shales from Canada. Nine species are recognised, eight of which have been recovered from rocks in North America and one from Russia. Description ''Hesperornis'' was a large bird, measuring about long and weighing around . It had virtually no wings, and swam with its powerful hind legs. Studies on the feet initially indicated that ''Hesperornis'' and kin had lobed toes similar to modern-day grebes, as opposed to webbed toes as seen in most aquatic birds such as loons. More recent work looking at the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Canadaga
''Canadaga'' (meaning "Canadian bird") is a flightless bird genus from the Late Cretaceous. The single known species is ''Canadaga arctica''. It lived in the shallow seas around what today is Bylot and Devon Islands in Nunavut, Canada. Its fossils were found in rocks dated to the Campanian to mid-Maastrichtian age, about 67 million years ago. It was found in the Kanguk Formation It was a member of the Hesperornithes, flightless toothed seabirds of the Cretaceous. Among these, it belonged to the Hesperornithidae, along with '' Hesperornis'', the well-known namesake genus. Description ''C. arctica'' is one of the largest known members of the Hesperornithes, reaching a length of . It also represents one of the last known members of the lineage. Unlike its relatives which are mainly known from subtropical or tropical waters, this species seems to have ranged in temperate or even subarctic areas. The species is described from 3 associated cervical vertebrae, one caudal vertebra a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Enaliornithidae
''Enaliornis'' is a genus of hesperornithine which lived during the late Albian to the early Cenomanian, making them the oldest known hesperornithines. Fossils have been found near Cambridge, England. Due to its lack of certain hesperornithid apomorphies, they were much more "conventional" birds and were initially held to be Gaviiformes (loons/divers). Description Based on the remnants that have been studied, it has not been determined if these birds had teeth like the others from this order. However, they were believed to not have well-developed wings. Like other hesperornithines, they probably had lobed feet for swimming, rather than webbed feet.Lim, J. D., Zhou, Z., Martin, L. D., Baek, K. S., & Yang, S. Y. (2000). The oldest known tracks of web-footed birds from the Lower Cretaceous of South Korea. ''Naturwissenschaften'', 87(6), 256-259. Classification ''Enaliornis'' was originally named '' Pelagornis'' ("sea bird") by Seeley in 1866, but that name was preoccupied by a M ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Brodavidae
''Brodavis'' is a genus of freshwater hesperornithiform birds known from the Late Cretaceous (possibly Campanian and Maastrichtian stage) of North America and Asia. It was first described and named by Larry D. Martin, Evgeny N. Kurochkin and Tim T. Tokaryk in 2012 and assigned to a new monogeneric family, Brodavidae. Four species were described and assigned to ''Brodavis''. The type species, ''B. americanus'', is known from the holotype left metatarsal, RSM P 2315.1 which was collected in the Maastrichtian-age Frenchman Formation of Canada. ''B. baileyi'' is known from the holotype left metatarsal, UNSM 50665, which was collected in the Maastrichtian-age Hell Creek Formation of South Dakota, United States (dated to between 66.8 and 66 Ma agoLongrich, N.R., Tokaryk, T. and Field, D.J. (2011). "Mass extinction of birds at the Cretaceous–Paleogene (K–Pg) boundary." ''Proceedings of the National Academy of Sciences'', 108(37): 15253-15257. ) ''B. mongoliensis ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hesperornis Regalis
''Hesperornis'' (meaning "western bird") is a genus of cormorant-like Ornithuran that spanned throughout the Campanian age, and possibly even up to the early Maastrichtian age, of the Late Cretaceous period. One of the lesser-known discoveries of the paleontologist O. C. Marsh in the late 19th century Bone Wars, it was an early find in the history of avian paleontology. Locations for ''Hesperornis'' fossils include the Late Cretaceous marine limestones from Kansas and the marine shales from Canada. Nine species are recognised, eight of which have been recovered from rocks in North America and one from Russia. Description ''Hesperornis'' was a large bird, measuring about long and weighing around . It had virtually no wings, and swam with its powerful hind legs. Studies on the feet initially indicated that ''Hesperornis'' and kin had lobed toes similar to modern-day grebes, as opposed to webbed toes as seen in most aquatic birds such as loons. More recent work looking at the m ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Parahesperornis
''Parahesperornis'' is a genus of prehistoric flightless birds from the Late Cretaceous. Its range in space and time may have been extensive, but its remains are rather few and far between, at least compared with its contemporary relatives in ''Hesperornis''. Remains are known from central North America, namely the former shallows of the Western Interior Seaway in Kansas. Found only in the upper Niobrara Chalk, these are from around the Coniacian-Santonian boundary, 85–82 million years ago (mya). ''Parahesperornis alexi'' (Martin, 1984) was long lumped with specimen YPM 1478, described initially as ''Hesperornis gracilis'' and later moved to the monotypic genus ''Hargeria'' (Lucas, 1903). It then turned out that this genus' description actually referred to specimen KUVP 2287, which eventually became the holotype of ''P. alexi''. Nonetheless, the taxon description of ''Hargeria'' was about ''"Hesperornis" gracilis'' exclusively, and thus despite the misidentification it appli ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hesperornis
''Hesperornis'' (meaning "western bird") is a genus of cormorant-like Ornithuran that spanned throughout the Campanian age, and possibly even up to the early Maastrichtian age, of the Late Cretaceous period. One of the lesser-known discoveries of the paleontologist O. C. Marsh in the late 19th century Bone Wars, it was an early find in the history of avian paleontology. Locations for ''Hesperornis'' fossils include the Late Cretaceous marine limestones from Kansas and the marine shales from Canada. Nine species are recognised, eight of which have been recovered from rocks in North America and one from Russia. Description ''Hesperornis'' was a large bird, measuring about long and weighing around . It had virtually no wings, and swam with its powerful hind legs. Studies on the feet initially indicated that ''Hesperornis'' and kin had lobed toes similar to modern-day grebes, as opposed to webbed toes as seen in most aquatic birds such as loons. More recent work looking at the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fumicollis
''Fumicollis'' is a genus of prehistoric flightless birds from the Late Cretaceous (Coniacian-Santonian) Niobrara Chalk of Kansas. Description Diagnostic traits of ''Fumicollis'' include presacral vertebrae with expanded ventral processes, an elongate pelvis with reduced acetabulum (acetabulum width: pelvis length is approximately 0.096 meters), a femur with expanded lateral condyle (transverse extent of condyle over 75% of midshaft width) and moderately expanded trochanter. The genus name refers to the Smoky Hill Chalk Member of the Niobrara Chalk in which it was found.Bell A, Chiappe LM (2015) Identification of a New Hesperornithiform from the Cretaceous Niobrara Chalk and Implications for Ecologic Diversity among Early Diving Birds. PLoS ONE 10(11): e0141690. https://doi.org/10.1371/journal.pone.0141690 Discovery The holotype of ''Fumicollis'', USNM 20030, was found by Harold Shepherd and George Sternberg in 1937 in the Smoky Hill Member of the Niobrara Chalk of Logan County, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Asiahesperornis
''Asiahesperornis'' is a prehistoric foot-propelled diving bird, diving toothed flightless bird genus from the Late Cretaceous. The single known species is ''Asiahesperornis bazhanovi''. It lived in what today is Kazakhstan, at its time the shores of the shallow Turgai Sea. It was a member of the Hesperornithes, flightless toothed seabirds of the Cretaceous. Its exact relationships are not completely resolved, but it probably belongs into the Hesperornithidae just like ''Hesperornis'', well known from the Western Interior Seaway that covered most of the US Midwest in the Mesozoic. Its name is derived from its findings in Asia. References Bird genera Extinct flightless birds Fossil taxa described in 1991 Hesperornithes Late Cretaceous birds of Asia {{paleo-bird-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Potamornis
''Potamornis'' is a prehistoric bird genus that dated back to the late Maastrichtian age of the late Cretaceous period. Its scrappy remains were found in the Lance Formation at Buck Creek, USA, and additional possible remains were found in the upper Hell Creek Formation of Montana, dated to the Danian age of the Paleogene period, though these may have been reworked. A single species was named and described in 2001: ''Potamornis skutchi''. This was almost certainly a member of the Hesperornithes, the hefty and toothed flightless diving birds of the Mesozoic seas. Its precise relationships are not all too clear; the quadrate bone is unique in some respects but apparently shares more apomorphies with the family Hesperornithidae - the "typical" Hesperornithes - in cladistic analysis.Mortimer (2004) Consequently, it might be considered a fossil hesperornithid with a different feeding specialization. Though it was heavily built like many (flying and flightless) diving birds, it weighed ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
