Procompsognathus

The fragmentary and poorly preserved skeleton of Procompsognathus was found in the Middle Stubensandstein member of the Löwenstein Formation at the Weiße Steinbruch, the quarry of Albert Burrer on the northern slopes of the Stromberg region near Pfaffenhofen in Württemberg, Germany.E. Fraas. 1907. Aetosaurus crassicauda n. sp. nebst Beobachtungen über das Becken der Aetosaurier [Aetosaurus crassicauda n. sp. together with observations on the pelvis of aetosaurs]. Mitteilungen aus dem Königlichen Naturalien-Kabinett zu Stuttgart 42:101-109 The discovery was made by Albert Burrer in the spring of 1909 in white sandstone and gray/blue marl sediments that were deposited during the Norian stage of the Triassic period, approximately 210 million years ago.

The holotype SMNS 12591, consisted of three blocks of sandstone: one showed a small, seven-centimetre-long, severely crushed skull with lower jaws. The second and third contained the partly articulated remains of a postcranial skeleton, including twenty-nine vertebrae of the neck, back and tail; ribs; elements of the shoulder girdle and a forelimb; an ilium; both pubis and the hindlimbs. It represents an adult individual.

Burrer sent the specimen to Professor Eberhard Fraas of the königliche Stuttgarter Naturalienkabinett. In a lecture on 9 October 1911, Fraas referred to it by the name "Hallopus celerrimus", considering it a jumping form of dinosaur that was approximately {{Convert|60|cm|ft|1|abbr=on}} long, and was associated with the origin of birds.Fraas, E., 1911, "Die schwäbische Dinosaurier", Jahreshefte des Vereins für vaterländische Naturkunde in Württemberg 1912: LXVI-LXVII Later, Fraas decided to use a different name in the official publication.Pompeckj, J.F., 1915, "Zur Erinnerung an Eberhard Fraas und an sein Werk", Jahreshefte des Vereins für vaterländische Naturkunde in Württemberg 1924: XXXIII Fraas in 1913 named the genus Procompsognathus with as type species, Procompsognathus triassicus.Fraas, E., 1913, "Die neuesten Dinosaurierfunde in der schwäbischen Trias", Naturwissenschaften 1(45): 1097-1100 The type specimen is housed in the collection of the State Museum of Natural History in Stuttgart, Germany.

In 1921, Friedrich von Huene referred two more specimens, both also found in the Burrer quarry, in 1908, to Procompsognathus: SMNS 12352, a partial skull and lower jaws from a larger individual than the holotype, and SMNS 12352a, an isolated left hand.Von Huene, F., 1921, "Neue Pseudosuchier und Coelurosaurier aus dem württembergischen Keuper", Acta Zoologica 2: 329-403

The genus name Procompsognathus, means "before elegant jaw", and is derived from the name of another dinosaur, Compsognathus. A later (Jurassic) small predatory dinosaur, Compsognathus takes its name from the Greek word kompsos (κομψός) which can be rendered as "elegant", "refined" or "dainty" and the Greek word gnathos (γνάθος) which means "jaw". The prefix Pro (προ) implies "before" or "ancestor of", although this direct lineage was not supported by subsequent research. The specific name triassicus refers to the geologic time period to which this dinosaur belongs, the Triassic.{{cite book | author = Liddell, Henry George and Robert Scott | year = 1980 | title = A Greek-English Lexicon | publisher = Oxford University Press | location = United Kingdom | isbn = 0-19-910207-4| edition = Abridged }}

File:Procompsognathus.jpg]]

Procompsognathus may have been about {{convert|1|m|ft}} long,Holtz, Thomas R. Jr. (2011) Dinosaurs: The Most Complete, Up-to-Date Encyclopedia for Dinosaur Lovers of All Ages, [http://www.geol.umd.edu/~tholtz/dinoappendix/HoltzappendixWinter2010.pdf Winter 2010 Appendix.] though Fraas in 1913 estimated a length of {{Convert|75|cm|ft|1|abbr=on}}. In 2010 Gregory S. Paul gave an estimate of {{convert|1|kg|lbs}} for the weight with a length of {{convert|1.1|m|ft}}.Paul, G.S., 2010, The Princeton Field Guide to Dinosaurs, Princeton University Press p. 72 In 2016, the holotype gained estimates of 1.3 kg and 28 cm in height at the hips.Molina-Pérez & Larramendi 2016. Récords y curiosidades de los dinosaurios Terópodos y otros dinosauromorfos, Larousse. Barcelona, Spain p. 23 A biped, Procompsognathus had long hind legs, short arms, large clawed hands, a long slender snout with many small teeth, and a stiff tail. The femur discovered for the type specimen of this genus measures 93mm and the tibia, 112mm. The tibia is approximately 20% longer than the femur in Procompsognathus, an adaptation which has been strongly correlated with the development of cursorial habits in dinosaurs, suggesting that they were good runners.Coombs, W. P., Jr. 1978. Theoretical aspects of cursorial adaptations in dinosaurs. The Quarterly Review of Biology 53:393–418.

In 1998 Chatterjee noted that the skull of Procompsognathus possesses a suite of theropod synapomorphies, which included:

• the presence of an accessory maxillary fenestra
• the vomers are fused rostrally and are extended considerably forward to the choana
• the single quadrate head is received completely by squamosal without paroccipital contact
• the lateroshenoid possesses a transverse postorbital process
• the orbitosphenoids are fused

In 2000, Rauhut noted that its scapula is more slender than that of Coelophysis bauri.

While it is undoubtedly a small, bipedal carnivore, the extremely poor preservation of the only known Procompsognathus fossil makes its exact identity difficult to determine. Fraas originally assigned it to the Dinosauria. In 1923 Franz Nopcsa coined a Procompsognathinae, and in 1929 von Huene created a Procompsognathidae, though these concepts are today rarely used. In 1932 von Huene saw it as a member of the non-dinosaurian Pseudosuchia.von Huene, F., 1932, Die fossile Reptil-Ordnung Saurischia, ihre Entwicklung und Geschichte. Monographien für Geologie und Paläontologie, 4, pp. 361 It has since then usually been considered a theropod dinosaur, with some exceptions. In 1992 Paul Sereno and Rupert Wild stated that the holotype specimen consisted of fossils from two separate animals: the postcranial skeleton would be a theropod, likely a coelophysoid related to Segisaurus, but the skull and the von Huene specimens they referred to the basal crocodylomorph Saltoposuchus connectens.{{cite journal |doi=10.1080/02724634.1992.10011473 |title=Procompsognathus: theropod, "thecodont" or both? |journal=Journal of Vertebrate Paleontology |author1=Sereno, Paul C. |author2=Wild, Rupert |volume=12 |issue=4 |date=December 15, 1992 |pages=435–458}} However, in 1993 Sankar Chatterjee after further preparation refuted their assessment and regarded the skull as that of a theropod similar to Megapnosaurus, and demonstrated that it could not have been a crocodylomorph, as it lacks the landmark features of this group.Chatterjee, S., 1993, "Procompsognathus from the Triassic of Germany is not a crocodylomorph", Journal of Vertebrate Paleontology 13(3): 29AChatterjee, S., 1998, "Reassessment of the Procompsognathus skull", p. 6 in: Wolberg, D.L., Gittis, K., Miller, S., Carey, L., and A. Raynor (eds.), Dinofest International. The Academy of Natural Sciences, Philadelphia Sereno (1997) and Ezcurra and Novas (2007) conducted phylogenetic analysis that supported the placement of Procompsognathus in the taxon Coelophysidae.P. C. Sereno. 1997. The origin and evolution of dinosaurs. Annual Review of Earth and Planetary Sciences 25:435-489M. D. Ezcurra and F. E. Novas. 2007. Phylogenetic relationships of the Triassic theropod Zupaysaurus rougieri from NW Argentina. Historical Biology 19(1):35-72 This genus may be most closely related to Segisaurus halli.Carrano, M.T., Hutchinson, J.R., & Sampson, S.D. 2005. New information on Segisaurus halli, a small theropod dinosaur from the Early Jurassic of Arizona. Journal of Vertebrate Paleontology 25(4): 835-849.

Much controversy has arisen however, about the association with the later material referred by von Huene. In 1982 John Ostrom claimed that SMNS 12352 and SMNS 12352a originated from a taxon different from the holotype. In 2006 and 2008 Fabien Knoll concluded that SMNS 12352 represented a crocodylomorph and SMNS 12352a a crocodylomorph or some other basal archosaur. The postcranial skeleton, for which he reserved the inventory number SMNS 12591, was a coelophysoid; and the skull, now indicated with the number SMNS 12591a, a perhaps more derived theropod, possibly a basal member of the Tetanurae.Knoll, F. & Schoch, R., 2006, "Does Procompsognathus have a head? Systematics of an enigmatic Triassic taxon", Journal of Vertebrate Paleontology 26: 86AKnoll, F., 2008, "On the Procompsognathus postcranium (Late Triassic, Germany)", Geobios 41: 779-786 In 2012 Knoll after a CAT-scan reaffirmed that SMNS 12352 was a crocodylomorph, but established it was different from Saltoposuchus.Knoll, F. & Schoch, R., 2012, "CT scanning, rapid prototyping and re-examination of a partial skull of a basal crocodylomorph from the Late Triassic of Germany", Swiss Journal of Geosciences 105: 109-115

Oliver Rauhut and Axel Hungerbuhler (2000) noted features of the vertebrae which suggest that Procompsognathus may be a coelophysid or ceratosaur,Rauhut, O. and Hungerbuhler, A. (2000). "A review of European Triassic theropods." Gaia 15, 75-88 and Carrano et al. (2005), in their re-study of the related genus Segisaurus, found both Segisaurus and Procompsognathus to belong to the Coelophysidae within Dinosauria.Carrano, M.T, Hutchinson, J.R, Sampson, S.D. (2005). "New information on Segisaurus halli, a small theropod dinosaur from the Early Jurassic of Arizona." Journal of Vertebrate Paleontology. 25(4):835-849 In 2004 David Allen considered Procompsognathus to be a primitive, non-dinosaurian ornithodiran.Allen, D. (2004). "The phylogenetic status of Procompsognathus revisited." Journal of Vertebrate Paleontology, 24(3): 34A

Procompsognathus lived in a relatively dry, inland environment and may have eaten insects, lizards and other small prey.Frances Freedman & Tony Gibbons, 1997, Looking at-- Procompsognathus: a dinosaur from the Triassic period, Gareth Stevens Pub., 1 January 1997, pp. 24 Contemporaries of Procompsognathus included the coelophysoids Halticosaurus and Dolichosuchus, as well as the Sauropodomorphs Plateosaurus gracilis and Efraasia minor. Weishampel, et al. (2004) noted that theropod tracks and fossils of an unnamed herrerasaur genus are known from the Lower Stubensandstein.Baden-Wurrtemberg, Germany; 1. Lower Stubensandstein," in Weishampel, et al. (2004). Page 524.

File:Misc-procompsognathus-amoswolfe.jpg

{{see also|Compsognathus#In popular culture}}

Procompsognathus appears in the novel Jurassic Park and its sequel The Lost World by Michael Crichton. The species is sometimes referred to as "compys" by the characters. While the author invents a venomous bite for Procompsognathus with soporific effects, there is no evidence to support venom in Procompsognathus.{{cite journal|author=Bennington, J Bret|year=1996|title=Errors in the Movie "Jurassic Park"|journal =American Paleontologist|volume=4|pages=4–7 | issue=2}}

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{{Theropoda|N.}}

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Category:Coelophysoidea

Category:Norian life

Category:Late Triassic dinosaurs of Europe

Category:Triassic Germany

Category:Fossils of Germany

Category:Fossil taxa described in 1913

Category:Taxa named by Eberhard Fraas