Vulcanodontidae

Vulcanodon in a plastic live presentation

  • Africa

Vulcanodon

Tazoudasaurus

Shunosaurus

Omeisaurus

Neosauropoda

The Vulcanodontidae is a family of primitive sauropod dinosaurs. It was originally set up by Cooper ( 1984) to summarize the early sauropods Vulcanodon and Barapasaurus. In subsequent years, the Vulcanodontidae were other genera attributed provisionally.

According to more recent analyzes ( Upchurch, 1995), however, the validity of the family was questioned because Barapasaurus was much more closely related than later sauropods with Vulcanodon. Barapasaurus has now klaffifiziert within the group of Eusauropoden, a group that includes all sauropods with, except very basal genera such Vulcanodon.

In 2004, the new, very primitive sauropod Tazoudasaurus been described, although there are significant similarities with Vulcanodon were found. To substantiate these similarities, these researchers Vulcanodontidae reinvented as a sister group of the Eusauropoden that includes Vulcanodon and Tazoudasaurus. However, today's writers usually do not follow this suggestion and consider the Vulcanodontidae thus remains as invalid. In the following description which refers to the grouping Vulcanodontidae Vulcanodon - Tazoudasaurus.

Description and systematics

Both Vulcanodon and Tazoudasaurus are known by relatively good skeletal remains: While Vulcanodon of a partial skeleton from Zimbabwe is known, we know from Tazoudasaurus two partial skeletons from the High Atlas of Morocco. Tazoudasaurus is also the only one so far found non- Eusauropode from which good skull material is known. Although it was previously thought that Vulcanodon comes from the Hettangian, new studies show that it actually comes from the Toarcian; that he is a contemporary of Tazoudasaurus.

Both genera belong to the most primitive sauropod known, and show many features, which were otherwise found only in prosauropods. To view the well-preserved skull remains of Tazoudasaurus still a forwardly tapering skull, wherein the non- overlapping teeth over the entire length of the lower jaw went. Later sauropods had a rounded snout with overlapping teeth, which are usually located only in the anterior region of the jaw. Although it definitely is quadrupede ( four-legged ) animals at Tazoudasaurus and Vulcanodon were the metatarsal bones ( metatarsals ) of Vulcanodon compared to those of other sauropods very long ( more than a third of the tibia ) and are thus similar to those of the prosauropods and theropods. Had Eusauropoden, as further adaptation to a four-footed life, only short metatarsal ( one fourth of the tibia ), the almost horizontal pads ( semidigitigrade ). Both Vulcanodon and Tazoudasaurus distinguished by some common primitive features ( plesiomorphies ) that are unknown in other sauropods; for example, the toe bones are longer than they are wide, and the lower end of the pubis ( pubic bone ) is an oblique, apron -like structure.

Other genres that are traditionally ascribed to the Vulcanodontidae

There are a number of other genera, which are traditionally associated with the Vulcanodontidae. Many of these genera are dubium as a noun, its validity is therefore uncertain - among which are the only known through a pine Chinshakiangosaurus, the well-known by a partial skeleton Kunmingosaurus and known by three fragmentary bones Zizhongosaurus. The position of these genera remains unclear.

Although the found in Germany, known by leg bones Zwergsauropode Ohmdenosaurus applies mostly as a valid genus, its position outside the Eusauropoden is, however, only temporary. Kotasaurus from India has recently been included in phylogenetic studies and therefore is considered as a primitive sauropod outside the Eusauropoda.

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