Aiolornis
Aiolornis | |
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Scientific classification | |
Domain: | Eukaryota |
Kingdom: | Animalia |
Phylum: | Chordata |
Class: | Aves |
Order: | Cathartiformes |
Family: | †Teratornithidae |
Genus: | †Aiolornis Campbell, Scott & Springer, 1999 |
Species: | †A. incredibilis
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Binomial name | |
†Aiolornis incredibilis (Howard, 1952)
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Synonyms | |
Teratornis incredibilis Howard, 1952 |
Aiolornis incredibilis is an extinct species of
History of discovery
The first Aiolornis material, described in 1952, was a cuneiform bone found in Smith Creek Cave, White Pine County, which is located 34 miles north of Baker, Nevada. The fossil was found to be from the Quaternary, and similarities with Teratornis merriami were noted in the description, hence the usage of the name T. incredibilis in the original description of the bird. The specimen was deemed distinct enough to warrant the naming of a new species based on its sheer size and other differences. The holotype specimen (on which the species is based) is around 40% larger than the same bone in T. merriami.[1]
In a redescription published in 1999, the species was moved into its own genus, Aiolornis, as A. incredibilis. Prior to this redescription, four additional specimens had been referred to T. incredibilis, although they were not diagnostic. There is also a lack of certainty on whether all of this material actually belongs to Aiolornis, due to the fragmentary nature of the fossils and the large timespan they represent. The fossils include the proximal end of an
The 1999 paper also refers a new bone to the species, a partial humerus (upper arm bone). The specimen was collected at Quintin Lake in April 1993, which is located approximately 1 km northeast of Murrieta, Riverside County, California. It differs from that of T. merriami in multiple aspects. The many differences between A. incredibilis and T. merriami supported the erection of the new genus Aiolornis for the former.[2]
Description
This section relies largely or entirely upon a single source.(April 2022) ) |
Aiolornis is classified as a teratorn, and its past affiliation with the much better preserved Teratornis allows for inferences about its appearance. It is usually depicted as a larger version of Teratornis. Aiolornis differs from Teratornis in a number of places, most obvious of which is size. Its wingspan is estimated to have been between 5 and 5.5 meters, and its weight at around 23 kg, which make it one of the largest, if not the largest, flight-capable bird from North America.[2]
The holotype material differs from that of T. merriami in a few key ways. For instance, present on the os carpi ulnare of Aiolornis is a prominent ridge, which forms the end of the facies articularis ulnaris and extends further beyond this, coming close to the attachment point for the ulno-ulnocarpal ligament. This attachment point is also proportionally longer than the same point in Teratornis, and it protrudes more prominently from the bone. The facies articularis ulnaris is also slightly more concave than that of Teratornis, with the dorsal rim lower than the ventral rim.[2]
The partial humerus described in the 1999 paper also differs from that of T. merriami and that of Argentavis magnificens in a number of ways, but most prominently in the fact that the facies dorsalis is fairly flat for the length of the attachment of the M. latissimus dorsi, becoming slightly convex near its distal end, and that the facies posterioris and facies dorsalis meet at a near right angle, with line of insertion of the M. latissimus dorsi following a well-defined "corner" of the margo anteriodorsalis.[2]
Classification
Aiolornis is classified within Teratornithidae,[1][2] which is a family in the order Cathartiformes. The order also includes the extinct and extant New World vultures.
References
- ^ a b Howard, Hildegarde (1952). "The prehistoric avifauna of Smith Creek Cave, Nevada, with a description of a new gigantic raptor". Bulletin of the Southern California Academy of Sciences. 51: 50–54 – via Biodiversity Heritage Library.
- ^ a b c d e f Campbell, Kenneth, Scott, Eric & Springer, Kathleen (1999). "A new genus for the incredible teratorn". Smithsonian Contributions to Paleobiology. 89: 169–175 – via Researchgate.
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