Champsosaurus
Extinct gharial-like reptile from the Cretaceous and Paleogene.
Wikipedia / Wikimedia Commons
Champsosaurus is an extinct genus of crocodile-like choristodere reptile known from the Late Cretaceous and early Paleogene periods of North America and Europe. It was the first member of the Choristodera to be described, named by Edward Drinker Cope in 1876 from isolated vertebrae found in Montana. The morphology of Champsosaurus resembles that of gharials, with a long, elongated snout, and it was native to freshwater environments where it likely preyed on fish.
- named_by
- Edward Drinker Cope
- year_named
- 1876
- time_period
- Late Cretaceous to early Paleogene (Campanian–Paleocene)
- location
- North America and Europe
- type_species
- Champsosaurus annectens (considered dubious)
- largest_species
- Champsosaurus gigas (3–3.5 m long)
- typical_length
- about 1.50 m
Lore & Background
Champsosaurus was named by Edward Drinker Cope in 1876 from isolated vertebrae found in Late Cretaceous strata of the Judith River Formation in Fergus County, Montana. Cope designated C. annectens as the type species, though the vertebrae are now considered undiagnostic to species level, making it a nomen vanum or nomen dubium. Barnum Brown in 1905 described the first complete remains and noted that some earlier species were based on eroded, non-diagnostic vertebrae. Brown named two species: C. ambulator and C. laramiensis from the Hell Creek Formation. Subsequent researchers added species from Canada and Europe, including C. albertensis, C. natator, C. dolloi, C. gigas, C. tenuis, and C. lindoei. Sixteen species have been named, of which seven are presently considered valid.
Reader's Guide
Champsosaurus holds significance as the first described member of the Choristodera, a group of aquatic reptiles. Its fossils have been found across North America and Europe, spanning the Late Cretaceous to late Paleocene, with tentative remains from the high Canadian Arctic during a time of extreme warmth. The genus is characterized by a flattened skull with a long, gharial-like snout, and adaptations for aquatic life, including a streamlined body and heavy gastralia. Internal cranial anatomy suggests good olfactory capabilities and sensitivity to low-frequency vibrations, but poor hearing of airborne sounds. Skin impressions show small pustulate and rhomboid scales without osteoderms. The classification of Champsosaurus within Neochoristodera is well supported, but relationships among its members remain uncertain, often recovered as a polytomy. The type species is considered dubious, and the only named European species, C. dolloi, was deemed too fragmentary to warrant a new species by some later researchers.
Did You Know?
- Champsosaurus was the first member of the Choristodera to be described.
- The name is thought to come from an Ancient Greek source saying an Egyptian word for 'crocodiles' and the Greek word for 'lizard'.
- The type species Champsosaurus annectens is considered a nomen vanum or nomen dubium because its vertebrae are undiagnostic.
- Champsosaurus gigas, the largest species, reached 3–3.5 m in length.
More in Extinct Archosaurs 1-24
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