Lithornithidae

Lithornithidae Temporal range: Paleocene-Eocene, 56–40Ma PreꞒ Ꞓ O S D C P T J K Pg N Possible Cretaceous reccord
Pseudocrypturus cercanaxius fossil cast, Zoologisk Museum, Copenhagen
Scientific classification
Kingdom:	Animalia
Phylum:	Chordata
Class:	Aves
Order:	†Lithornithiformes
Family:	†Lithornithidae Houde, 1988
Genera
Lithornis Paracathartes Promusophaga Tom Harrisson & Walker, 1977 Pseudocrypturus

Lithornithidae is an extinct, possibly paraphyletic^[1] clade of early paleognath birds. They are known from fossils dating to the Upper Paleocene through the Middle Eocene of North America and Europe, with possible Late Cretaceous representatives.^[2][3] All are extinct today.^[4]

Woodcut of the Lithornis vulturinus holotype

Lithornithids had long, slender, bills for probing. They closely resembled modern tinamous. They possessed a rhynchokinetic skull with relatively unfused cranial bones, a weakly fused pygostyle and a splenial. They had a strongly developed keel on the sternum. The smaller members in genus Lithornis and Pseudocrypturus were good fliers, but the heavier Paracathartes was probably only a facultative flier. The unguals were more curved than in tinamous and probably allowed better perching in trees.

The order Lithornithiformes was erected by Dr. Peter Houde in 1988. Three genera are included; Lithornis, Paracathartes, and Pseudocrypturus. There are eight known species.^[4] Promusophaga (Harrisson & Walker, 1977) may belong in Lithornithiformes too.

References