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Vulcanodon (meaning "volcano tooth") is an extinct genus of sauropod dinosaur from the Early Jurassic uppermost Forest Sandstone of southern Africa. The only known species is V. karibaensis. Discovered in 1969 in Zimbabwe, it was regarded as the earliest known sauropod for decades, and is still one of the most primitive genera that has been discovered.
As a quadrupedal, ground-dwelling herbivore, Vulcanodon already showed the typical sauropod body plan with column-like legs and a long neck and tail. It was smaller than most other sauropods, measuring approximately in length. Vulcanodon is known from a fragmentary skeleton including much of the pelvis, hindlimbs, forearms, and tail, but lacking the trunk and neck as well as the skull. Originally, this genus was believed to be a "prosauropod" because of the knife-shaped teeth found near its , which fit in with the idea that they were omnivorous. Scientists now know that the teeth belonged to an unidentified theropod that may have scavenged on the Vulcanodon carrion, which is now known to be a true sauropod. Upon the discovery of the related Tazoudasaurus, both animals were unified in the family Vulcanodontidae, although this has not been universally accepted.
As one of the earliest and basalmost sauropods, it is important for understanding the early evolution of this group. Sauropods descend from basal sauropodomorpha (informally called "prosauropods"), which were primitively Bipedalism (two-legged). While Vulcanodon already was fully Quadrupedalism (four-legged), its limb proportions were intermediate between those of its prosauropod ancestors and those of later, more derived sauropods. Its forelimbs were much more similar to later sauropods than basal sauropodomorphs because they are straight, much more gracile, and the proximal end of the ulna is v-shaped. Unfortunately, no skull or neck of Vulcanodon is known, although it is otherwise very well known.
The hallux (the first toe of the foot) showed a large claw that was flattened laterally, as seen in "prosauropods". However, the claws of the second and third toe were unusual in being nail-like and broader than deep. This feature was also found in the probably closely related Tazoudasaurus, but is absent in all other sauropods. The feet of Vulcanodon were plantigrade as in later sauropods (where both the digits and part of the metatarsals contact the ground), a derived feature not found in more basal sauropods like Isanosaurus. However, they also retained primitive features, like the fact that the phalanx were not reduced.
Many of the features found in sauropods that basal sauropodomorphs lack are related to the change in body size. The greatest regions affected by this are the hind limbs and pelvis. For example, an elongating of the ilium, size reduction of the lesser trochanter shelf, and semiplantigrade posture are some features that indicate the amount and positioning of leg muscles being modified. Vulcanodon possessed these features, the latter of which is seen earliest in it. However, Vulcanodon does not have reduced distal phalanges, which are seen in Shunosaurus and all more derived sauropods. This means that while the muscle positioning of its legs were changing, they had not yet reduced in the distal region of the limb.
The skeleton (catalogue number QG24) has been found weathering out of a hill slope and was partially eroded by surface exponation and plant roots, erroneously documented as sandwiched between two basalt layers. It includes the pelvis and sacrum, most of the left hind limb and foot, a right thigh bone, and twelve anterior tail vertebrae. These remains pertain to a single individual as they were all found articulated (still connected together). Additionally, several disarticulated bones were found, including the right forearm and some metacarpus and Phalanx bone from both the right and left forefeet, probably also pertaining to this individual. Later, the site was revisited by the scientists Geoffrey Bond and Michael Cooper, who were able to collect additional remains including a scapula (specimen QG152, a shoulder blade) and a fragment of a neck vertebra. These remains show that more than one individual was present, and it is possible that they do not pertain to Vulcanodon at all. Today, the Vulcanodon remains are stored in the Natural History Museum of Zimbabwe in Bulawayo.
Raath (1972) noted the discovery of nine fragmentary carnivorous teeth near the pelvic region of the skeleton. He argued that the Vulcanodon carcass might have been embedded with the head and neck bended backwards above the pelvis, a posture called death pose that is frequently seen in dinosaur skeletons. The teeth would have been the only preserved elements of the skull. However, as shown by Cooper (1984), these teeth do not pertain to Vulcanodon but to a theropod dinosaur that may have scavenged on the Vulcanodon carcass.
Originally, Michael Raath (1972) described Vulcanodon not as a sauropod but as an derived trait, specialized prosauropod, possibly of the family Melanorosauridae. According to Raath, the sauropod-like limb proportions in Vulcanodon evolved independently from those of true sauropods (through convergent evolution). He argued that primitive features of the pelvis as well as the knife-shaped teeth preclude a classification within the Sauropoda. The teeth, however, are now known to belong to a theropod. Arthur Cruickshank (1975) was the first to show that Vulcanodon was indeed a sauropod, arguing that the fifth metatarsal bone was equally long as the remaining metatarsals, a condition seen in other sauropods but not in prosauropods.Cruickshank, A. R. I. 1975. Origin of sauropod dinosaurs. South African Journal of Sciences, 71, 89-90. Today, Vulcanodon is universally accepted to be one of the most basal (primitive) members of Sauropoda.
Michael Cooper (1984) erected a new family, the Vulcanodontidae, which he regarded as the "rootstock" for later sauropod families. Originally, the Vulcanodontidae included Vulcanodon and the Barapasaurus, but subsequent studies attributed a number of other, much more fragmentary early sauropod genera to this family, including Ohmdenosaurus and Zizhongosaurus. Paul Upchurch (1995) showed that Barapasaurus was more closely related to later, more advanced sauropods than to Vulcanodon, rendering the Vulcanodontidae polyphyletic and therefore invalid.
The exact relationships with other basal sauropod genera remain unclear. Ronan Allain and colleagues (2004, 2008) found that Vulcanodon is most closely related to Tazoudasaurus, a newly discovered sauropod genus from Morocco. These researchers suggested reintroducing the name Vulcanodontidae to name the clade containing Vulcanodon and Tazoudasaurus. However, this sister group between Tazoudasaurus and Vulcanodon could not be confirmed by other analyses.
Adam Yates (2004) described a single sauropod tail vertebra from the Upper Elliot Formation of South Africa that may belong to a genus closely related to Vulcanodon. The Upper Elliot Formation is famous for its abundant fossils of the prosauropod Massospondylus.
Vulcanodon in a cladogram after Nair et al., 2012:
It was long assumed that Vulcanodon lived during the lowermost (earliest) part of the Jurassic (the Hettangian stage) or at the Triassic–Jurassic boundary, approximately 200 million years ago. Therefore, it was regarded as the earliest sauropod known, until the discovery of the even older Late Triassic Isanosaurus was announced in 2000. Adam Yates (2004) has recently shown that Vulcanodon is actually much younger than previously thought, dating to the uppermost (latest) part of the Lower Jurassic during the Toarcian stage, approximately 175–183 million years ago. Thus, it is contemporary to the closely related Tazoudasaurus. As was assumed that the locality of Vulcanodon itself cannot be dated radiometrically because of weathering of the lavas, it would roughly be a contemporary to Karoo lavas from other localities, as the entire sequence of volcanic eruptions was finished within one million years. In 2018 was revelated that as in 2016 Lake Kariba hosted record-low water levels the unit were accessible to be studied and confirmed that the holotype came from the uppermost Forest Sandstone, being as old as the Rhaetian or as young as the Pliensbachian, with a Sinemurian-Pliensbachian Midpoint.
Vulcanodon is the only named dinosaur from the Vulcanodon beds. Cooper (1984) noted that the habitat was desert-like, as indicated by aeolian (wind-blown) sands of the Forest Sandstone Formation, which underlies the "Vulcanodon beds". The sediments in which Vulcanodon was found may represent distal alluvial fan deposits which levelled off into a desert landscape, which may have contained lakes during the wet season. The individual may have roamed the shores of that cut into the alluvial fan deposits, unless the carcass was transported to the locality it was found by flooding.
Initially, sauropods were thought to be mainly aquatic, inhabiting lush peat swamps and being captive to the buoyancy of water to support their giant body weights. In 1984, Cooper pointed out that Vulcanodon, the most primitive sauropod known at that time, lived in a desert like environment and therefore must have been terrestrial. This indicated that the large body size of sauropods, as already seen in Vulcanodon, had not evolved as an adaptation to an aquatic life style.
(2025). 9780756699109, Dorling Kindersley. ISBN 9780756699109
(2025). 9780253355089, Indiana University Press. ISBN 9780253355089
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