The glyptocystitoid rhombiferan Sprinkleocystis ektopios new genus and species is described from the Middle Ordovician (Caradoc) Benbolt Formation of Tennessee. This species is characterized by having four ambulacra bearing only terminal brachioles, the absence of lateral 5, and protuberant pectinirhombs and periproct. Many of its features are considered typical of the family Cheirocrinidae whereas others are more characteristic of the Glyptocystitidae. Its small size and simple ambulacral and pectinirhomb structures suggest a paedomorphic evolutionary origin, and its thecal morphology further suggests that the validity of a separate Cheirocrinidae and Glyptocystitidae may need reevaluation.
How to translate text using browser tools
1 January 2003
HETEROCHRONY AND PAEDOMORPHIC MORPHOLOGY OF SPRINKLEOCYSTIS EKTOPIOS, NEW GENUS AND SPECIES, (RHOMBIFERA, GLYPTOCYSTIDA) FROM THE MIDDLE ORDOVICIAN (CARADOC) OF TENNESSEE
THOMAS W. BROADHEAD,
COLIN D. SUMRALL
ACCESS THE FULL ARTICLE