Liliensternus

''Liliensternus'' is an extinct genus of basal neotheropod dinosaur that lived approximately 210 million years ago during the latter part of the Triassic Period in what is now Germany. ''Liliensternus'' was a moderate-sized, bipedal, ground-dwelling carnivore, that could grow up to long. It is the best represented Triassic theropod from Europe and one of the largest known.Rauhut, O.M.W. & A. Hungerbuhler, 1998, "A review of European Triassic theropods". ''Gaia'' 15. 75-88.

Description

''Liliensternus'' was approximately long, and may have weighed about . Other estimates suggest that ''Liliensternus'' was at best long and weighed at most. The remains of two specimens of ''Liliensternus'' together form a syntype series with inventory number MB.R.2175, and consist of the partial and fragmentary skeletons of at least two individuals, containing elements of the skull, the lower jaws, the vertebrae and the appendicular skeleton. The tibia (409 mm) is shorter than the femur (440 mm) in both ''Dilophosaurus'' and ''Liliensternus'', unlike those of coelophysid taxa, such as ''Coelophysis''. Paul (1988) noted that based on its appearance, ''Liliensternus'' could be considered to be an intermediate between ''Coelophysis'' and ''Dilophosaurus''. Although the skull is not well known, many reconstructions have ''Liliensternus'' with a crest similar to that observed in ''Dilophosaurus''. Its ilium (hip bone) is unusually short, as is the case with ''Dilophosaurus''. ''Liliensternus'' has five fingers, much like its contemporaries, but its fourth and fifth digits are smaller than the rest, a possible transitional stage between the five fingered theropods of the Triassic and the three fingered theropods of the Jurassic.

Rauhut et al. (1998) noted that the remains may represent a juvenile or subadult individual based on the presence of only two fused sacrals and the fact that the neurocentral sutures are still visible in the vertebrae.

A diagnosis is a statement of the anatomical features of an organism (or group) that collectively distinguish it from all other organisms. Some, but not all, of the features in a diagnosis are also autapomorphies. An autapomorphy is a distinctive anatomical feature that is unique to a given organism or group. According to Rauhut (2000), ''Liliensternus'' can be distinguished based on the following features: the cervical vertebrae feature a broad rounded ridge that extends from the posterior end of the diapophyses to the posteroventral end of the vertebral centrum, one pair of pleurocoels in the cervical vertebrae, a less developed infradiapophyseal fossa, the absence of a horizontal ridge at the basis of the cervical neural spines, absence of a lateral bulge on the ilium.

Discovery

The specimens of ''Liliensternus'', designated as the syntype series HMN BM.R.2175, were recovered near Großer Gleichberg in the Trossingen Formation of the Middle Keuper Group in Thuringia, Germany, together with remains of ''Ruehleia''. The syntypes were discovered by Count Hugo Rühle von Lilienstern in the winter of 1932/1933 in marlstone (lime-rich mudstone) deposited in the Norian stage of the Late Triassic period, approximately 228 to 208 million years ago.F. v. Huene, 1934, "Ein neuer Coelurosaurier in der thüringischen Trias", ''Paläontologische Zeitschrift'' 16(3/4): 145-170 A left metatarsal later assigned to this genus, also deposited in the Norian, was collected in 1834 in the sandstone of the Trossingen Formation in Bayern, Germany. This metatarsal was originally described as a manual or pedal element by Meyer (1855) and a pubic fragment by Huene (1908) of ''Plateosaurus'', and the material was re-identified as a proximal metatarsal belonging to ''Liliensternus'' by Moser in 2003. Sander (1992) referred additional material to ''Liliensternus'', which was thought to have been collected in 1961 grey/green marlstone from the Löwenstein Formation in Aargau, Switzerland, which is considered to also be from the Norian stage of the Late Triassic period. A tooth referred to this ''Liliensternus'', deposited in the Norian, and collected in 1913 in dark red mudstone from the Löwenstein Formation in Baden-Württemberg, Germany. The only material assigned to this genus from later strata was discovered in 1913 in blue claystone from the Rhaetian stage of the Late Triassic, in the Trossingen Formation from Sachsen-Anhalt, Germany, approximately 208 to 201 million years ago. The ''Liliensternus'' specimens remained in Hugo Rühle von Lilienstern's castle until 1969 when they were transferred to the collection of the Natural History Museum of Berlin, their present location.

The genus and specific names ''Liliensternus liliensterni'' are derived from the last name of count, amateur paleontologist, and medical doctor, Hugo Rühle von Lilienstern. This dinosaur was named in his honor for his furthering paleontology in Germany by founding a paleontological museum in his castle in Bedheim, on 1 July 1934. ''Liliensternus'' was described by Friedrich von Huene in 1934.F. v. Huene. 1934. Ein neuer Coelurosaurier in der thüringischen Trias new coelurosaur in the Thuringian Trias ''Paläontologische Zeitschrift'' 16(3/4):145-170 Because it was originally named by von Huene as a member of the genus ''Halticosaurus'', the type species of the genus ''Liliensternus'' is ''Halticosaurus liliensterni''; the ''combinatio nova'' is ''Liliensternus liliensterni''.

In 1993 Gilles Cuny and Peter Galton described a new species that they assigned to this genus, ''Liliensternus airelensis.'' Other researchers began to notice differences between ''L. airelensis'' and the type species, ''L. liliensterni'', and in 2007, Martin Ezcurra and Cuny assigned the material to its own genus, '' Lophostropheus''.

Classification

In 1934, Huene described two skeletons assigning them the name ''Halticosaurus liliensterni'', but in 1984 Samuel Paul Welles concluded that the type species of ''Halticosaurus'', ''H. longotarsus'', was a ''nomen dubium''. Most of what had been written in the literature about ''Halticosaurus'' in fact regarded ''H. liliensterni''. Welles therefore erected a new genus: ''Liliensternus'', the name again honoring Rühle von Lilienstern.
The new species name became ''Liliensternus liliensterni''. Rowe (1989) found that ''Liliensternus'' is more derived than ''Dilophosaurus''. A second species named in 1993 by Cuny and Galton for fragmentary remains found in France, ''Liliensternus airelensis'', which had an extra pair of cervical pleurocoels, was in 2007 reassigned to a separate genus, '' Lophostropheus''. Originally assigned to the Halticosauridae, ''Liliensternus'' is today considered a basal member of the Neotheropoda.

The following evolutionary tree illustrates a synthesis of the relationships of the early theropod groups compiled by Hendrickx ''et al.'' in 2015, including the position of ''Liliensternus'' in which all studies concur.Hendrickx, C., Hartman, S.A., & Mateus, O. (2015). An Overview of Non- Avian Theropod Discoveries and Classification. ''PalArch’s Journal of Vertebrate Palaeontology'', 12(1): 1-73.

Paleoecology

''Liliensternus'' was an active bipedal carnivore that could have preyed on the larger herbivores like ''Plateosaurus'', which were present in its paleoenvironment. The material discovered in Switzerland, Sachsen-Anhalt, Germany and the tooth from Baden-Württemberg, Germany, suggest that ''Liliensternus'' inhabited ancient floodplains that were abundant with reptiles, therapsids, and ''Plateosaurus''.O. Jaekel. 1913. Über die Wirbeltierfunde in der oberen Trias von Halberstadt n the vertebrate finds in the Upper Triassic of Halberstadt Paläontologische Zeitschrift 1:155-215 Paul (1988) noted that ''Liliensternus'' used its slashing tooth arrays to disable prosauropods and its speed to catch swift ornithischians.

See also

* Timeline of coelophysoid research

References

External links

''Liliensternus'' on the Dinosaur Mailing List

{{Taxonbar, from=Q132620

Coelophysoids
Late Triassic dinosaurs of Europe
Triassic Germany
Fossils of Germany
Fossil taxa described in 1984
Taxa named by Samuel Paul Welles