Protozoa - Nassellaria - Eucyrtidiidae
Named by Carter.
Original description: Test broadly conical, usually with four to five post-abdominal chambers. Cephalis small, conical, usually without a rudimentary horn. Cephalis imperforate, thorax and abdomen sparsely perforate covered with a layer of microgranular silica. Post-abdominal chambers trapezoidal, rapidly increasing in width an added, final chamber closed with a large ellipsoidal cap. Pore frames on post-abdominal chambers polygonal increasing in size distally.
Original remarks: This species differs from Lantus obesus (Yeh) 1987 in having a shorter, less inflated final post-abdominal chamber with smaller pore frames, and in lacking a constriction between the final two chambers. L. praeobesus n. sp. is the oldest species of Lantus included in this catalogue; it first appears in the basal Pliensbachian and is abundant throughout the stage.
Hemicryptocephalis dengquensis Li is questionably synonymized with L. praeobesus n. sp. because the description of the former is unclear (see remarks under genus Lantus).
Etymology: From the Latin, prae (prefix) and obesus (adj.) before obesus.
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 Lantus according to S. Gorican et al. 2006
Sister taxa: Lantus intermedius, Lantus obesus, Lantus sixi, Lantus sutnal
Type specimen: GSC 111725. Its type locality is Maude Island, west of Ells Bay; GSC loc. C-304566, which is in a Pliensbachian marine limestone in the Fannin Formation of Canada.
Ecology: passively mobile planktonic omnivore
Distribution:
• Jurassic of Canada (43: British Columbia collections), Japan (3)
Total: 46 collections each including a single occurrence
Specimen images are retrieved through the ePANDDA API.
Click image to enlarge. Click to access iDigBio record.