Lithornis
| Lithornis | |
|---|---|
| |
| Woodcut of theL. vulturinusholotype | |
Scientific classification
| |
| Domain: | Eukaryota |
| Kingdom: | Animalia |
| Phylum: | Chordata |
| Class: | Aves |
| Infraclass: | Palaeognathae |
| Order: | †Lithornithiformes |
| Family: | †Lithornithidae |
| Genus: | †Lithornis Owen,1840[1] |
| Species | |
Lithornisis agenusof extinctpaleognathousbirds. AlthoughLithorniswas able to fly well, their closest relatives are the extanttinamous(which are poor flyers) andratites(which areflightless birds).
Fossils ofLithornisare known with certainty from the UpperPaleocenethrough theMiddle Eocene,but their fossil record may extend to the late Cretaceous.Lithornisis from ancient Greek for 'stone bird', as it is one of the first fossil birds to become widely discussed. Presumably closely related genera areParacathartesandPseudocrypturus.
Species
[edit]
Sixspecieshave been recognized in modern times; undescribed ones are also likely to exist. The supposedtarsometatarsuspiece from which"Lithornis" emuinuswas described is actually ahumerusfragment of the giantpseudotooth birdDasornis.[2]
Lithornis celetius
[edit]L. celetiusis from the Bangtail Quarry, Sedan Quadrangle,Park County, Montana,and was described by Peter Houde (1988). It is from theFort Union Formation,which is earliestTiffanian,LatePaleocene.The type fossil is USNM 290601.[2]
L. celetiuswas of average size for the genus, and the nameCeletiusis derived from theGreekwordkeletiona race horse for which thetype localityis also named.[2]
Lithornis hookeri
[edit]Harrison and Walker originally labeled the fossil as belonging to the speciesPediorallus barbaraein 1977. In 1984, Harrison redescribed the fossil as coming from a new speciesPediorallus hookeri,and later that year it was moved toLithornis hookeri.[2][3]L. hookeriis the smallest of the Lithornithidae.[2]
Lithornis nasi
[edit]W. George collected the originalfossilin the Division ALondon Clay,North Sea BasinatWalton on the Naze,Essex,England.The fossil was described by Harrison in 1984 as a rail,Pediorallus nasi,but was later moved toLithornis nasi.L. nasiis larger thanL. hookeriandL. plebius.[2]In 2015,L. nasiwas proposed to be ajunior synonymofL. vulturinusbecause its differences in shape and size from the latter species were concluded to more likely represent intraspecific variation.[4]
Lithornis plebius
[edit]L. plebiusis from the same locality asL. promiscuusand was also described by Peter Houde (1988). The type specimen is USNM 336534.
Lithornis promiscuus
[edit]L. promiscuushastype specimenUSNM 336535 and was described by Peter Houde (1988). It is from the ClarkQuadrangle,Park County, Wyoming, USA. It is from the Willwood Formation, which is earliestEocenein age. An egg, USNM 336570, is known forL. celetiusas well.
Lithornis vulturinus
[edit]L. vulturinuswas described as a vulture by Owen (1840) from the holotype fossil 955 738 - TM 024 717. The fossil was collected fromEarly EoceneLondon Claydeposits on the Isle of Sheppey, Kent, England by J. Hunter before 1793. This fossil was destroyed by bombing inWorld War II.Numerous isolated fossil bones ofLithornis vulturinuswere incorrectly described anew, such asParvigyps praecoxandPromusophaga magnifica- the supposed earliest vulture and turaco, while others were referred to existing families of neognathous birds. Aneotype(BMNH A 5204) was erected to replace the holotype in 1988 by Houde, who for the first time diagnosed it as a paleognath based on complete three-dimensional skulls and skeletons of congeners from North America. An exceptionally preserved specimen was collected from Denmark and cataloged as MGUH 26770.[5]
Palaeobiology
[edit]Lithornis'wing bones are similar to those of storks and vultures, meaning that unlike modern tinamous it was capable of soaring flight.[6][7][8]
In a study aboutratiteendocasts,Lithornisranks among the taxa with well developed olfactory lobes. This is consistent with a nocturnal, forest-dwelling lifestyle, though as much all volant birds it retains large optical lobes.[9]
Unlike modern tinamous,Lithornishas toe claws and reversed halluxes that allow for efficient perching.[8]
Several egg fossils have been attributed toLithornis.[8][10]Their eggshells are, perhaps unsurprisingly, noted as being "ratite-like".[11]
References
[edit]Footnotes
- ^Hinton, A.C. (1939)
- ^abcdefHoude, P. (1988)
- ^Mayr, G. (2008)
- ^Bourdon, Estelle; Lindow, Bent (20 October 2015)."A redescription of Lithornis vulturinus (Aves, Palaeognathae) from the Early Eocene Fur Formation of Denmark".Zootaxa.4032(5).doi:10.11646/zootaxa.4032.5.2.ISSN1175-5334.PMID26624382.Retrieved7 May2024.
- ^Leonard, L. & Van Tuinen, M. (2005)
- ^Houde, Peter W. (1988). "Paleognathous Birds from the Early Tertiary of the Northern Hemisphere". Publications of the Nuttall Ornithological Club (Cambridge, MA)
- ^Gerald Mayr, The Birds from the Paleocene Fissure Filling of Walbeck (Germany), Journal of Vertebrate Paleontology 27(2):394–408, June 2007:https://ichthyoconodon.files.wordpress.com/2018/11/flight.png
- ^abcPaleogene Fossil Birds
- ^Torres, C. R.; Clarke, J. A. (2018). "Nocturnal giants: evolution of the sensory ecology in elephant birds and other palaeognaths inferred from digital brain reconstructions". Proceedings of the Royal Society B: Biological Sciences. 285 (1890): 20181540. doi:10.1098/rspb.2018.1540.
- ^Houde, Peter W. (1988). "Paleognathous Birds from the Early Tertiary of the Northern Hemisphere". Publications of the Nuttall Ornithological Club (Cambridge, MA) 22.
- ^Gerald Grellet-Tinner and Gareth J. Dyke, The eggshell of the Eocene bird Lithornis, Acta Palaeontologica Polonica 50 (4), 2005: 831-835
Sources
- Hinton, A. C.; Lang, W. D.; et al. (1939). Neave, Sheffield Airey (ed.).Nomenclator Zoologicus.Vol. 2. Regents Park, London: Zoological Society of London. p. 975.
- Houde, Peter (1988)."Paleognathous Birds from the Early Tertiary of the Northern Hemisphere"(PDF).Publications of the Nuttall Ornithological Club.22.Cambridge Massachusetts, USA: Nuttall Ornithological Club: 34–35.
- Leonard, Leona; Gareth J. Dyke; Marcel Van Tuinen (October 2005)."A new specimen of the fossil palaeognathLithornisfrom the Lower Eocene of Denmark "(PDF).American Museum Novitates(3491): 1–11.
- Mayr, Gerald (2008)."First substantial Middle Eocene record of the Lithornithidae (Aves): A postcranial skeleton from Messel (Germany)"(PDF).Annales de Paléontologie.94.Elsevier Masson SAS.: 29–37.doi:10.1016/j.annpal.2007.12.004.Archived fromthe original(PDF)on June 10, 2011.RetrievedJan 18,2010.
