Dino of the Week: Vulcanodon

 

Type Species: Vulcanodon karibaensis

Classification: Dinosauria - Saurischia - Sauropoda - Gravisauria - Vulcanodontidae

Time Period: Early Jurassic

Location: South Africa

Diet: Herbivore

Vulcanodon was a sauropod that lived in South Africa during the Sinemurian to Toarcian stages of the Early Jurassic. At this point in time, southern Africa was a hotspot of volcanic activity that threaded much of southern Africa and Antarctica’s landscape with extensive flood basalts (‘lava flows’). Vulcanodon was discovered in one of these ‘volcano beds’, a fossil-bearing sediment unit within the Batoka Formation, which is composed primarily of flood basalts. Hence its name: ‘volcano tooth.’ The habitat in which it was found was desert-like in the late Early Jurassic, as is shown by the wind-blown sands of the Forest Sandstone Formation that underlies the volcano beds. Scientists speculate that the sediments in which Vulcanodon died may represent distal alluvial fan deposits that leveled off into a desert landscape. This region may have contained lakes during the wet season, and Vulcanodon may have roamed the shores of wadis that cut into the alluvial fans. It’s possible that this sauropod fed upon the plants that sprouted around watering holes; or maybe it gorged itself sick during the wet seasons and survived on its fat reserves during the dry seasons. Several teeth from an unknown theropod were found among its remains, indicating that it had been scavenged after death. 

Vulcanodon’s discovery in an arid environment prompted quite a stir. For decades it was assumed that sauropods were mainly aquatic, thriving in lush peat swamps and requiring the buoyancy of water to support their bodyweight. In 1984 it was pointed out that Vulcanodon – at that point the most primitive known sauropod – lived in a desert-like environment and would’ve thus been wholly terrestrial. This implied that sauropod gigantism wasn’t an adaptation to an aquatic lifestyle. Vulcanodon helped nail the lid on the coffin of ‘aquatic’ sauropods. For a long time it was considered the earliest true sauropod, at least until the discovery of the Late Triassic Isanosaurus in 2000. Though Vulcanodon was thought to have lived in the Hettangian stage of the Early Jurassic (the Jurassic’s earliest stage), further study has shown that it actually lived much later, in the last stage (the Toarcian) of the Early Jurassic. 

Though a true sauropod, Vulcanodon has features highlighting its close relations with prosauropods. It was a relatively small sauropod, measuring thirty-six feet in length. Though it was already fully quadrupedal with column-like legs, its limb proportions were intermediate between its prosauropod ancestors and those of more derived sauropods; yet its forelimbs were much more similar to later sauropods than prosauropods, because they were straight and slender.