page_title: Camarasaurus
section_title: Species
hierarchical_section_title: Camarasaurus / History of discovery / Species
caption_attribution_description: Camarasaurus supremus (#1) bones being exvataed by Oramel Lucas for Edward Drinker Cope, c. 1877.
context_page_description: Camarasaurus was a genus of quadrupedal, herbivorous dinosaurs. It was the most common of the giant sauropods to be found in North America. Its fossil remains have been found in the Morrison Formation of Colorado and Utah, dating to the Late Jurassic epoch, between 155 and 145 million years ago.
  Camarasaurus presented a distinctive cranial profile of a blunt snout and an arched skull that was remarkably square. It likely travelled in herds, or at least in family groups.
  The name means "chambered lizard", referring to the hollow chambers in its vertebrae.
context_section_description: The type species of Camarasaurus is Cope's original species, C. supremus (meaning "the biggest chambered lizard"), named in 1877. Other species since discovered include C. grandis ("grand chambered lizard") in 1877, C. lentus in 1889, and C. lewisi (originally described as a new genus Cathetosaurus) in 1988.
  C. supremus, as its name suggests, is the largest known species of Camarasaurus and one of the most massive sauropods known from the late Jurassic Morrison Formation. Except for its huge size, it was nearly indistinguishable from C. lentus. C. supremus was not typical of the genus as a whole, and is  known only from the latest, uppermost parts of the formation. Both C. grandis and C. lentus were smaller, as well as occurring in the earlier stages of the Morrison.
  Stratigraphic evidence suggests that chronological sequence aligned with the physical differences between the three species, and it describes an evolutionary progression within the Morrison Formation. C. grandis is the oldest species and occurred in the lowest rock layers of the Morrison. C. lentus appeared later, co-existing with C. grandis for several million years, possibly due to different ecological niches as suggested by differences in the spinal anatomy of the two species. At a later stage, C. grandis disappeared from the rock record, leaving only C. lentus. Then C. lentus, too, disappeared; at the same time, C. supremus appeared in the uppermost layers. This immediate succession of species, as well as the very close similarity between the two, suggests that C. supremus may have evolved directly from C. lentus, representing  a larger, later-surviving population of animals.
  C. lewisi species was originally named as Cathetosaurus lewisi and later synonymized with Camarasaurus. A 2013 analysis split the two genera again.
caption: C. supremus quarry in 1877
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