Pronunciation: ak-e-LOW-uh-SOR-us
Meaning: Achelous' lizard
Author/s: Scott Sampson (1994)
Synonyms: None known
First Discovery: Montana, USA
Discovery Chart Position: #404
Achelousaurus horneri
Achelousaurus is an early cretaceous centrosaurine ceratopsian, a quadrupedal "horn faced" plant muncher, and is named after Achelous: a shapeshifting river God from Greek mythology. At the mercy of testosterone, Achelous incited the wrath of Heracles by groping his wife Deianeira and during the ensuing battle he was smacked senseless by the furious demi-god and had one of his horns ripped off. Achelousaurus on the other hand (err... face) didn't have horns per se, just bony brillo-pads where one might expect ceratopsian brow and snout horns to be but, like most centrosaurines, its frill was adorned with horn-like prongs, in this case two, right on the apex.
Its snout "horn" inparticular has prompted plenty of speculation, with one theory being another snappy reference to Achelous and his shape-shifting tendencies. Early reports suggested that the forward-curving "can-opener" nose horn of fellow-Montanan centrosaurine Einiosaurus carried on curving until it was reabsorbed by the snout then expanded to virtually fuse with the brow stumps and formed a huge bony boss, a hallmark of the latest-living centrosaurine Pachyrhinosaurus, and that Achelousaurus, neither horned nor impressiveley bossed, was a stepping stone amidst this evolution in progress. Whether or not that is the case, all three are currently each other's closest relatives and dwell within a centrosaurine sub-group or "tribe" known as Pachyrhinosaurini.
Its snout "horn" inparticular has prompted plenty of speculation, with one theory being another snappy reference to Achelous and his shape-shifting tendencies. Early reports suggested that the forward-curving "can-opener" nose horn of fellow-Montanan centrosaurine Einiosaurus carried on curving until it was reabsorbed by the snout then expanded to virtually fuse with the brow stumps and formed a huge bony boss, a hallmark of the latest-living centrosaurine Pachyrhinosaurus, and that Achelousaurus, neither horned nor impressiveley bossed, was a stepping stone amidst this evolution in progress. Whether or not that is the case, all three are currently each other's closest relatives and dwell within a centrosaurine sub-group or "tribe" known as Pachyrhinosaurini.
Horner's Achelous LizardEtymology
Achelousaurus is derived from "Achelous" (a Greek river deity) and "sauros" (lizard). The species epithet, Horneri, honors American Paleontologist Jack horner who made some major discoveries in the area, including "egg mountain": the home of Maiasaura.
Discovery
The first remains of Achelousaurus were discovered in the Two Medicine Formation at Landslide Butte, 40km northwest of Cut Bank, Glacier County, Montana, U.S.A.The Holotype (MOR 485) is a partial skull. Referred material includes a partial skull, an almost complete vertebral column, a complete pelvis and sacrum, and a thighbone (MOR 591), and a partial skull, associated vertebrae and ribs (MOR 571), both found on Blacktail Creek, 30km south of Cut Bank. All specimens were found during Bozeman's Museum of the Rockies excavations.
Preparators
Carrie Ancell (Museum of the Rockies).
