Presbytery
| Presbytery | ||||||||||||
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Presbytery , living reconstruction |
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| Temporal occurrence | ||||||||||||
| Eocene | ||||||||||||
| 50 million years | ||||||||||||
| Locations | ||||||||||||
| Systematics | ||||||||||||
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| Scientific name | ||||||||||||
| Presbytery | ||||||||||||
| Wetmore , 1926 |
Presbyornis is an extinct bird from the order of the goose birds (Anseriformes). It was describedby Alexander Wetmore in 1926 after the discovery of incoherent fossil skeletons. Presbyornis shows features of various groups of birds, including flamingo-like, long legs and a duck-like beak. Wetmore assigned Presbyornis to the plover-like (Charadriiformes) and assumed that the flamingos and the goose birds emerged from this group.
In 1991, many contiguous skeletons of the bird were found in southwestern Wyoming and southeastern Utah in the Green River Formation . The deposit dates from the lower Eocene 50 million years ago. Another large collection of fossils was discovered in 1975 CE. a. by Alan Feduccia 150 km further, found in Canyon Creek, near the border between Colorado and Wyoming. Here the beaks are much better preserved and presbyornis has been recognized as a filtering primitive goose bird.
features
The skull, cranium, and beak of the presbyornis were duck-like, with the beak curved upwards; similar to the recent monkey duck , which, like presbyornis, feeds on algae and zooplankton .
The frontal and nasal bones were arranged in a V-shape, a feature that is only found in today's flamingos . This region of the Presbyornis skull is almost identical to that of a thirty-day-old Cuban Flamingo chick.
Upper arm bones (humerus), tibiotarsus and tarsometatarsus resembled those of the plover-like.
environment
Presbyorium fossils have always been found in high concentrations, along with broken eggshells. Similar to flamingos, the birds lived and brooded colonial in large groups on the banks of large lakes. In the same deposits of the Green River Formation, the remains of palm trees , crocodiles , softshell turtles , and about 50 species of fish, including the ray heliobatis , the herring-like Knightia , various perch- like , bald pike ( Amia sp.) And moon-eyes ( Eohiodon ) were found . The primitive frigate bird Limnofregata azygosternon was a possible predator of Presbyornis chicks.
Systematics
Presbyornithidae is part of the family Presbyornithidae, which belongs to the order of the goose birds (Anseriformes) , together with three other species, including Teviornis gobiensis from the Maastrichtian of the Nemegt formation in southern Mongolia .
literature
- Alan Feduccia: The Origin and Evolution of the Birds. 2nd Edition. Yale University Press, New Haven 1999, ISBN 0300078617
Individual evidence
- ^ Evgeny N. Kurochkin, Gareth J. Dyke, Alexandr A. Karhu: A New Presbyornithid Bird (Aves, Anseriformes) from the Late Cretaceous of Southern Mongolia. (PDF; 441 kB) In: American Museum Novitates. No. 3386, 2002, pp. 1-11.
