| Lithornis Temporal range: Paleocene-Eocene, 56–40 Ma |
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|---|---|
| Woodcut of the L. vulturinus holotype | |
| Scientific classification | |
| Kingdom: | Animalia |
| Phylum: | Chordata |
| Class: | Aves |
| Superorder: | Palaeognathae |
| Order: | †Lithornithiformes |
| Family: | †Lithornithidae |
| Genus: | †Lithornis Owen, 1840[1] |
| Species | |
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Lithornis celetius |
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Lithornis is a genus of extinct paleognathous birds. Lithornis were able to fly well, but are closely related to today's tinamous (which are poor flyers) and ratites (which are flightless birds).
Fossils of Lithornis are known from the Upper Paleocene through the Middle Eocene. "Lithornis" is from ancient Greek for "stone bird", as it was one of the first fossil birds to become widely discussed. Presumably closely related genera are Paracathartes, Pediorallus, Promusophaga and Pseudocrypturus.
Six species have been recognized in modern times, but not all may be valid; undescribed ones are also likely to exist. The supposed tarsometatarsus piece from which "Lithornis" emuinus was described is actually a humerus fragment of the giant pseudotooth bird Dasornis.[2]
Lithornis vulturinus
L. vulturinus was described by Owen (1840) from the holotype fossil 955 738 - TM 024 717. The fossil was collected from Early Eocene London Clay deposits on the Isle of Sheppey, Kent, England by J. Hunter before 1793. This fossil was destroyed by bombing in World War II. A neotype was erected by Houde in 1988, and the new fossil has catalog number BMNH A 5204. An exceptionally preserved specimen was collected from Denmark and cataloged as MGUH 26770.[3]
Lithornis hookeri L. hookeri was first described by Harrison (1984).[2][4]
Lithornis nasi
L. nasi was described by Harrison (1984),also.[2]
Lithornis celetius
L. celetius is from the Bangtail Quarry, Sedan Quadrangle, Park County, Montana, USA, and was described by Peter Houde (1988). It is from the Fort Union Formation, which is earliest Tiffanian, Late Paleocene. The type fossil is USNM 290601.[2]
Lithornis promiscuus
L. promiscuus has type specimen USNM 336535 and was described by Peter Houde (1988). It is from the Clark Quandrangle, Park County, Wyoming, USA. It is from the Willwood Formation, which is earliest Eocene in age. An egg, USNM 336570, is known for L. celetius as well.
Lithornis plebius
L. plebius is from the same locality as L. celetius and was also described by Peter Houde (1988). The type specimen is USNM 336534.