Protozoa - Spumellaria - Praeconocaryommidae
Named by Carter.
Original description: Large multi-layered cortical shell with prominent mammae. Distal surfaces of mammae small to medium in size, low to moderately raised, pentagonal to hexagonal in shape, with slightly rounded surfaces. Each mamma surrounded by six strong triangular pore frames whose vertices link with other mammae. Inner layer(s) of shell comprised of smaller irregular to subtriangular pore frames connected to the outer triangular pore frames forming a slightly depressed interconnecting meshwork. Short peripheral spines visible on some specimens. Central structure of test unknown.
Original remarks: Praeconocaryomma yakounensis n. sp. differs from P. sarahae n. sp. in possessing a larger test. Furthermore, the inner layer of pore frames connects to the outer triangular pore frames forming an interlocking meshwork rather than telescoping inward as in P. sarahae n. sp. In Queen Charlotte Islands, this is the oldest form (late Sinemurian) that can even questionably be assigned to the genus Praeconocaryomma Pessagno.
Etymology: Named for the type locality on the western bank of the Yakoun River, central Graham Island.
Full reference: S. Gorican, E. S. Carter, P. Dumitrica, P. A. Whalen, R. S. Hori, P. De Wever, L. O'Dogherty, A. Matsuoka, and J. Guex. 2006. Catalogue and systematics of Pliensbachian, Toarcian and Aalenian radiolarian genera and species 446
Belongs to Praeconocaryomma according to Carter 2006
Sister taxa: Praeconocaryomma bajaensis, Praeconocaryomma californiaensis, Praeconocaryomma copiosa, Praeconocaryomma decora, Praeconocaryomma hexagona, Praeconocaryomma jiangzeensis, Praeconocaryomma lipmanae, Praeconocaryomma mamillaria, Praeconocaryomma matsuokai, Praeconocaryomma media, Praeconocaryomma parvimamma, Praeconocaryomma sarahae, Praeconocaryomma scatebra, Praeconocaryomma splendida, Praeconocaryomma universa, Praeconocaryomma vivenkensis
Type specimen: GSC 111794 (pl. PRY06, fig. 1).
Ecology: passively mobile planktonic omnivore
Distribution:
• Jurassic of Canada (11: British Columbia collections), United States (2: Oregon)
Total: 13 collections each including a single occurrence
Specimen images are retrieved through the ePANDDA API.
Click image to enlarge. Click to access iDigBio record.