Search results
Results from the WOW.Com Content Network
Ichthyornithes is an extinct group of toothed avialan dinosaurs very closely related to the common ancestor of all modern birds.They are known from fossil remains found throughout the late Cretaceous period of North America, though only two genera, Ichthyornis and Janavis, are represented by complete enough fossils to have been named.
Their missing or vestigial hallux – like in ducks but unlike in pelicans which have all four toes fully developed and webbed – was held against a close relationship with pelicans. But as is known today, pelicans are closer to storks (which have a hallux but no webbing) than to pseudotooth birds and evolved their fully webbed toes independently.
The earliest birds with a modern pygostyle: a reduction and fusion of the tail vertebrae; possibly a paraphyletic group. Two types of pygostyle are known, a rod-shaped one found in Confuciusornithidae , Enantiornithes and some non-avian theropods such as Nomingia , and a plowshare -shaped one, only known in the lineage leading to modern birds.
This list of Mesozoic birds is a comprehensive list of all Mesozoic dinosaurs that have been assigned to the clade Avialae (birds, in the broadest sense). The list includes all commonly accepted genera, but also genera that are now considered invalid, doubtful (nomen dubium), or were not formally published (nomen nudum), as well as junior synonyms of more established names, and genera that are ...
Late Quaternary prehistoric birds are avian taxa that became extinct during the Late Quaternary – the Late Pleistocene or Early Holocene – and before recorded history, specifically before they could be studied alive by ornithological science. They had died out before the period of global scientific exploration that started in the late 15th ...
“They are the only group of birds that achieved the role of terrestrial apex predators, evolving species that basically conquered South America during the Miocene (about 23.03 million to 5.33 ...
In humans, the vermiform appendix is sometimes called a vestigial structure as it has lost much of its ancestral digestive function.. Vestigiality is the retention, during the process of evolution, of genetically determined structures or attributes that have lost some or all of the ancestral function in a given species. [1]
View of birds flying around the Bird Key, a private island on Biscayne Bay that is now for sale as environmentalists are upset, because developers could build on the island, displacing all the ...