Lophostropheus

Taxobox
name = "Lophostropheus"
fossil_range = Late Triassic-Early Jurassic
regnum = Animalia
phylum = Chordata
classis = Sauropsida
superordo = Dinosauria
ordo = Saurischia
subordo = Theropoda
superfamilia = Coelophysoidea
familia =
genus = "Lophostropheus"
binomial = "Lophostropheus airelensis"
binomial_authority = Ezcurra and Cuny, 2007

"Lophostropheus" (meaning "crest vertebrae") was a genus of coelophysoid dinosaur from the Rhaetian-Hettangian-age (Late Triassic-Early Jurassic) Moon-Airel Formation of Normandy, France. It is based on a partial skeleton first described in 1966 as a specimen of "Halticosaurus". It is one of the few dinosaurs known from rocks near the Triassic-Jurassic boundary.

The type species, "Lophostropheus airelensis", was formally described by Argentine paleontologist Martin Ezcurra of the Museo Argentino de Ciencias Naturales in Buenos Aires and French paleontologist Gilles Cuny of the Université Pierre et Marie Curie in Paris.

Description

"Lophostropheus" differs from other theropods in several ways. It has features reminiscent of more derived theropods, such as having a ball connection to the front of its neck vertebrae, a socket connection to the front of its tail vertebrae, and a vertical ridge on the ilium. These are all interpreted as convergences, however. It also has prominent crests on the tops and bottoms of its neck vertebrae (for which it was named), and an extra pair of cavities in its neck vertebrae, unlike "Liliensternus". It was closer to the coelophysids, including the well-known "Coelophysis", than to "Liliensternus".

History of discovery

In 1966, the French paleontologists C. Larsonneur and Albert-Félix de Lapparent described a partial theropod skeleton from the Triassic-Jurassic boundary of Normandy as "Halticosaurus" sp.cite journal |last=C. |first=Larsonneur |coauthors=and de Lapparent, Albert-Félix |year=1966 |title=Un dinosaurien carnivore, "Halticosaurus", dans le Rhétien d'Airel (Manche) |journal=Bulletin de la Société Linnéenne de Normandie |volume=7 |pages=108–117 |language=French ] This specimen, now held at the University of Caen, consisted of a tooth, five neck vertebrae, two vertebrae from the back, four sacral vertebrae, tail vertebrae, portions of all the pelvic bones, and an unidentified fragment.cite journal |last=Ezcurra |first=Martin D. |coauthors=and Cuny, Gilles |year=2007 |title=The coelophysoid "Lophostropheus airelensis", gen. nov.: a review of the systematics of "Liliensternus" "airelensis" from the Triassic-Jurassic boundary outcrops of Normandy (France) |journal=Journal of Vertebrate Paleontology |volume=27 |issue=1 |pages=73–86 |doi=10.1671/0272-4634(2007)27 [73:TCLAGN] 2.0.CO;2 |doilabel=10.1671/0272-4634(2007)27[73:TCLAGN]2.0.CO;2 ] It was reinterpreted in 1993 by Gilles Cuny and Peter Galton as belonging to a new species, assigned to "Liliensternus" and named "L. airelensis."cite journal |last=Cuny |first=Gilles |coauthors=and Galton, Peter M. |year=1993 |title=Revision of the Airel theropod dinosaur from the Triassic-Jurassic boundary (Normany, France) |journal=Neues Jahrbuch für Geologie und Paläontologie, Abhandlungen |volume=187 |issue=3 |pages=261–288 ] Other researchers began to notice differences between "L. airelensis" and the type species, "L. liliensterni",cite journal |last=Rauhut |first=Oliver W.M. |coauthors=and Hungerbühler, A. |year=2002 |title=A review of European Triassic theropods |journal=Gaia |volume=15 |pages=75–88 ] and in 2007, Martin Ezcurra and Cuny assigned it to its own genus, "Lophostropheus".

Paleobiology

"Lophostropheus", as a coelophysoid, would have been a small- to medium-sized bipedal carnivore,cite book |last=Tykoski |first=Ronald S. |coauthors=and Rowe, Timothy |editor=Weishampel, David B.; Dodson, Peter; and Osmólska, Halszka (eds.)|title=The Dinosauria |edition=2nd |year= 2004|publisher=University of California Press |location=Berkeley |isbn=0-520-24209-2 |pages=47-70 |chapter=Ceratosauria] probably comparable in size and habits to "Liliensternus" (best specimen estimated at 5.15 meters long, or 16.9 feet).cite book |last=Paul |first=Gregory S. |authorlink=Gregory S. Paul |title=Predatory Dinosaurs of the World |year=1988 |publisher=Simon & Schuster |location=New York |isbn=0-671-61946-2 |pages=p. 267 ] Very few dinosaurs are known from its time period; in fact, it is the only theropod genus known from good remains at the Triassic-Jurassic boundary.

ee also

*Triassic-Jurassic extinction event

References