Dracovenator (/ˌdrækoʊvɛˈneɪtər/) is agenus ofneotheropoddinosaur that lived approximately 201 to 199million years ago during the early part of theJurassicperiod in what is nowSouth Africa.Dracovenator was a medium-sized, moderately built, ground-dwelling,bipedalcarnivore, that could grow up to an estimated 5.5–6.5 metres (18–21 ft) in length and 250 kilograms (550 lb) in body mass. Its type specimen was based on only a partial skull that was recovered.
Drawing of the known skull bones. Scale bar equals 10 cm
The type materialBP/1/5243 forDracovenator was discovered at the "Upper Drumbo Farm" locality in the upperElliot Formation which is part of theStormberg Group inEastern Cape Province, South Africa. It was collected by James Kitching and Regent "Lucas" Huma in sandstone that was deposited during theHettangian stage of theJurassic period, approximately 201 to 199 million years ago. The paratype material BP/1/5278 (originally assigned toSyntarsus rhodesiensis) was discovered in 1981, also at theElliot Formation in pinkish-maroon silty mudstone that was deposited inHettangian sediments.[1] Both the holotype and paratype specimen were housed in the fossil collection of theEvolutionary Studies Institute, part of the School of Geosciences of theUniversity of the Witwatersrand, inJohannesburg, South Africa. Unfortunately the cranial material house at theEvolutionary Studies Institute was lost and no new fossils ofDracovenator have currently been found.[citation needed]
The genus name is a contraction of theLatin wordsdraco meaning "dragon", andvenator meaning "hunter"; thus, "dragon hunter". "Draco" refers to its discovery in the foothills ofDrakensberg, which is "Dragon's Mountain" in the Dutch language. Thespecific name,regenti, was named in the honor of the late Regent 'Lucas' Huma, who was Professor Kitching's field assistant.Dracovenator was described and named by Adam M. Yates in 2005 and thetype species isDracovenator regenti.
Dracovenator is estimated to have measured between 5.5 and 6.5 m (18 and 21 ft) in length and 250 kg (550 lb) in body mass.[2][3] The holotype specimen,BP/1/5243, consists of bothpremaxillae, a fragment of themaxilla, twodentary fragments, a partialsurangular bone, a partialangular bone, a partialprearticular bone, anarticular bone, and several teeth.Dracovenator has a kink in its upper jaws, between the maxilla and the premaxilla. The back end of the lower jaw features an array of lumps and bumps, a condition seen inDilophosaurus, but to a much smaller extent. Munyikwa and Raath (1999) reassigned paratype BP/1/5278, which was originally assigned toSyntarsus rhodesiensis, toDracovenator, a juvenile specimen which consists of bones from the front of the skull, teeth, and jaw bones.[1]
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. According to Yates (2005)Dracovenator can be distinguished based on the following characteristics: the presence of a large bilobedfossa surrounding a large lateral premaxillary foramen that is connected to the alveolar margin by a deep narrow channel; a deep, oblique notch on the lateral surface of the articular bone, separating the retroarticular process from the posterior margin of theglenoid, a particularly well-developed dorsal, tab-like processes on the articular bone—the first on the medial side, just posterior to the opening of the chorda tympanic foramen and the second on the lateral side on the anterolateral margin of the fossa for the m. depressor mandibulae.[4]
Yates (2005) assignedDracovenator to thecladeNeotheropoda.[4] The firstcladistic analysis found that this genus formed a clade with the basal theropodsDilophosaurus andZupaysaurus. The skull of the type specimen, exhibits a mosaic of both ancestral and derived theropod characteristics. The followingcladogram, based on the phylogenetic analysis conducted by Smith, Makovicky, Pol, Hammer, andCurrie in 2007, outlines the relationships ofDracovenator and its close relatives:[5]
^abMunyikwa and Raath, 1999. Further material of the ceratosaurian dinosaurSyntarsus from theElliot Formation (Early Jurassic) of South Africa.Palaeontologia Africana. 35:55–59.
^Paul, G. S. (2016).The Princeton Field Guide to Dinosaurs (2nd ed.). Princeton, New Jersey: Princeton University Press. p. 79.ISBN9780691167664.
^abA. M. Yates. 2005. A new theropod dinosaur from the Early Jurassic of South Africa and its implications for the early evolution of theropods. Palaeontologia Africana 41:105–122
^Smith, N.D., Makovicky, P.J., Pol, D., Hammer, W.R., andCurrie, P.J. (2007). "The dinosaurs of the Early Jurassic Hanson Formation of the Central Transantarctic Mountains: Phylogenetic review and synthesis." In Cooper, A.K. and Raymond, C.R. et al. (eds.), Antarctica: A Keystone in a Changing World––Online Proceedings of the 10th ISAES, USGS Open-File Report 2007-1047, Short Research Paper 003, 5 p.
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