Peltoceratinae
Encyclopedia
The Peltoceratinae comprise a subfamily in the Aspidoceratidae
, (middle and upper Jurassic perisphinctacean ammonites).
Genera in the Peltoceratinae have sharply ribbed inner whorls and outer whorls that bear spines or tubercles, or have coarse simple ribs. Among these are giant forms with simple peristomes (aperture openings) that occur along with smaller forms with lappets.
Derivation of the Peltoceratinae seems most likely to be from the Pseudoperisphinctinae.
Aspidoceratidae
The Aspidoceratidae comprise a family of middle and upper Jurassic ammonites that make up part of the superfamily Perisphinctaceae, characterized by evolute shells, commonly stocky, that tend to develop tubercles....
, (middle and upper Jurassic perisphinctacean ammonites).
Genera in the Peltoceratinae have sharply ribbed inner whorls and outer whorls that bear spines or tubercles, or have coarse simple ribs. Among these are giant forms with simple peristomes (aperture openings) that occur along with smaller forms with lappets.
Derivation of the Peltoceratinae seems most likely to be from the Pseudoperisphinctinae.
References
- Arkell et al, 1957. Mesozoic Ammonoidea. Treatise on Invertebrate Paleontology, Part L (Ammonoidea). Geol Soc of America and Univ Kansas Press.