Cryptops

Cryptops
	Found skeletal parts of cryptops .
Temporal occurrence
	Lower Cretaceous ( Aptium )
	126.3 to 112.9 million years
Locations
	Niger ( Elrhaz Formation );
Systematics
	Lizard dinosaur (Saurischia)
	Theropoda
	Ceratosauria
	Abelisauroidea
	Abelisauridae
	Cryptops
Scientific name
	Cryptops
	Sereno & Brusatte , 2008

Kryptops is a genus of theropod dinosaur from the group of Abelisauridae . So far, only a fragmentary skeleton is known from the Lower Cretaceous ( Aptium ) Niger . The only species is Kryptops palaios .

The name Kryptops ( Gr .: krypto - "hidden", ops - "face") refers to the pitted surface of the upper jaw, which indicates a possible covering of keratin . The second part of the species name, palaios (Greek "old"), indicates the high geological age compared to related genera.

features

Artistic live presentation of kryptops

Kryptops is estimated to be 6 to 7 meters long, making it about the same size as Majungasaurus . The upper jaw is estimated to be about 25 centimeters long, which indicates a skull about 50 centimeters long. The length of the skull in relation to the body was significantly smaller than that of better-known representatives of the Abelisauridae.

The paired upper jaw probably contained 17 or 18 teeth each in the living animal. The outer surface of the upper jaw is rough and has numerous pits pointing in different directions. This texturing could indicate that the integument covering the facial bones was made of keratin . In contrast to related genera such as rugops , these pits were relatively short ( autapomorphy ).

Systematics

Sereno and Brusatte carried out a cladistic analysis and tentatively classify Kryptops as an early and basic (original) representative of the Abelisauridae .

Abelisauridae cladogram (simplified from Sereno and Brusatte, 2008)

Abelisauridae

Cryptops

Rugops

Rajasaurus

	Majungasaurus

	Carnotaurus

Systematic position of cryptops .

Find

The only skeleton of Kryptops ( holotype , specimen number MNN GAD1) comes from the Gadoufaoua site of the Elrhaz Formation in the western edge of the Ténéré, southeast of Agadez . It consists of a left upper jaw , fragments of some vertebrae and ribs, and the pelvic girdle and sacrum . These fossils probably come from a single individual, since apart from two teeth no other vertebrate remains were discovered in the vicinity of the find. The pelvic girdle and sacrum were found in the original anatomical union. While most of the skeleton was found embedded in the rock matrix, the upper jaw was eroded and found about 15 meters away from the other bones .

Paleoecology

The Elrhaz Formation is home to diverse land vertebrate fauna. The most frequently discovered large theropod is the spinosauride Suchomimus ; further theropods include Eocarcharia and an as yet undescribed noasaurid . Herbivorous dinosaurs of the formation include the sauropod Nigersaurus and the ornithopods Ouranosaurus and Lurdusaurus . Furthermore, the remains of various crocodile relatives, turtles and bony fish, the remains of a hybodont shark and freshwater clams were found.

literature

Paul C. Sereno , Stephen L. Brusatte: Basal abelisaurid and carcharodontosaurid theropods from the Lower Cretaceous Elrhaz Formation of Niger. In: Acta Palaeontologica Polonica. Vol. 53, No. 1, 2008, ISSN 0567-7920 , pp. 15-46, doi : 10.4202 / app.2008.0102 .