Apsaravis
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Apsaravis Temporal range: Late Cretaceous, 78 Ma |
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| Scientific classification | |
| Kingdom: | Animalia |
| Phylum: | Chordata |
| Genus: |
†Apsaravis Norell & Clarke, 2001 |
| Species: | †A. ukhaana |
| Binomial name | |
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Apsaravis ukhaana Norell & Clarke, 2001 |
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Apsaravis is a Mesozoic bird genus from the Late Cretaceous. The single known species, Apsaravis ukhaana, lived about 78 million years ago, in the Campanian age of the Cretaceous period. Its fossilized remains were found in the Camel's Humps sublocality of the Djadokhta Formation, at Ukhaa Tolgod in the Gobi Desert of Mongolia. They were collected in the 1998 field season by the Mongolian Academy of Sciences/American Museum of Natural History Paleontological Expeditions. It was described by Norell and Clarke (2001).
Its habitat was presumably very arid open landscape much like it is today, perhaps hotter still and with more (but nonetheless intermittent) rain. Permanent freshwater would have been scarce.
Apsaravis is important in avian paleontology. It has provided evidence that is directly relevant to at least four issues:
The Sauriurae are a putative clade of primitive birds that includes Archaeopteryx, Confuciusornis, and Enantiornithes. It is thought by Feduccia and Martin to be phylogenetically separate from the Ornithurae and, thus, from modern birds.Apsaravis has features of both Sauriurae and Ornithurae. Apsaravis has several characters that place it near Aves (sensu Gauthier), including the presence of at least ten sacral vertebrae, a pubis and ischium that are closely appressed, distal pubes that do not touch, an 'obturator flange' on the ischium, loss of the cuppedicus muscle fossa on the ilium, a patellar groove on the distal femur, an anterior sternal keel, completely heterocoelus vertebrae, curved scapular shaft, and several features of the forelimb, ankle, and foot. Apsaravis also retains primitive characters shared with Enantiornithes and more basal theropods, including a narrow intercondylar groove and barrel-shaped condyles of the tibiotarsus, a dorsal fossa of the coracoid, into which the supracoracoideus nerve foramen opens, and several features of the humerus. This intermediate anatomy is evidence against the validity of the clade "Sauriurae".
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