Stygimoloch

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Stygimoloch
Reconstruction of the skull of Stygimoloch spinifer, exhibited in the Museum für Naturkunde Berlin

Reconstruction of the skull of Stygimoloch spinifer , exhibited in the Museum für Naturkunde Berlin

Temporal occurrence
Upper Cretaceous (late Maastrichtian )
69.9 to 66 million years
Locations
Systematics
Dinosaur (dinosauria)
Pelvic dinosaur (Ornithischia)
Cerapoda
Marginocephalia
Pachycephalosauria
Genre : Stygimoloch
Scientific name
Stygimoloch
Galton & Sues , 1983
Drawing reconstruction of a pachycephalosaur ("Triebold specimen") that has not yet been described, possibly a Stygimoloch

Stygimoloch is a genus of the bird pelvic dinosaur (Ornithischia) from the group of the Pachycephalosauria . Like all representatives of this group of dinosaurs, it had a thickened skull-roof, characteristic were the long spines on the back of the head. There is only one species, Stygimoloch spinifer .

features

Stygimoloch was a medium-sized pachycephalosaur with an estimated length of 3 meters.

As with all pachycephalosaurs, the thickened roof of the skull was formed from the fused frontal and parietal bones (frontoparietals), the top of the skull was arched and very pointed like hardly any other representative of this dinosaur group. The skull was decorated with numerous small bony bumps, including on the nasal and scale bones . At the back of the head there were also two 10 cm long, backward-protruding horns next to a few smaller horns.

Paleobiology

Presumably, as with all pachycephalosaurs, the hind legs were significantly longer than the front legs and Stygimoloch moved bipedally (two-legged). Like other representatives of this group, he may have kept his spine horizontal while running and the tail stiffened by ossified tendons served as a counterweight. Its diet was likely to have consisted mainly of plant material.

The function of the thickened skull roof and the spines is discussed. As with other pachycephalosaurs, it is considered that ramming duels were carried out with the skulls, for example for the mating privilege. Kenneth Carpenter counters this by saying that due to the bulging skull, the impact area was too small for such duels. He thinks it is conceivable that the animals tried to hit the flanks of their opponent in duels. Maryańska et al. think it is conceivable that in Stygimoloch, in contrast to other pachycephalosaurs, the top of the skull and the spines were only used for display and were not used in disputes.

Discovery and naming

Fossil remains of Stygimoloch were found in the US states of North Dakota , Wyoming and Montana , they are dated in the Upper Cretaceous (late Maastrichtian ) to an age of about 69 to 66 million years.

The genus was first described in 1983 by Galton & Sues , the type species and the only known species is S. spinifer . The generic name is derived from Styx , a river of hell in Greek mythology, and Moloch , a demon in the Hebrew tradition. It was named after the Hell Creek Formation (Hell Creek = "Höllenbach") in the US states of Montana and Wyoming, from whose rock five fragmentary skulls have so far been recovered.

Systematics

The systematic position of Stygimoloch within the Pachycephalosaurier is not exactly clarified. R. Sullivan classifies it as a close relative of Pachycephalosaurus and Dracorex in the Pachycephalosaurini, a cladistic study by Maryańska et al. sees in him, however, a more primitive representative. According to recent studies, Stygimoloch could be half-grown, almost sexually mature specimens of Pachycephalosaurus .

literature

Web links

Commons : Stygimoloch  - collection of images, videos and audio files

Individual evidence

  1. ↑ Gregory S. Paul : The Princeton Field Guide To Dinosaurs. Princeton University Press, Princeton NJ et al. 2010, ISBN 978-0-691-13720-9 , p. 244, online .
  2. ^ Science Daily New Analyzes Of Dinosaur Growth May Wipe Out One-Third Of Species
  3. ↑ scinexx the knowledge magazine One third of the dinosaur species wrong?