Lantus intermedius Gorican et al. 2006 (radiolarian)

Protozoa - Nassellaria - Eucyrtidiidae

Named by Carter.

Original description: Test conical, usually with four or five postabdominal chambers. Cephalis small, conical, apparently lacking horn. Cephalis imperforate, thorax and abdomen sparsely perforate covered with a layer of microgranular silica. Post-abdominal chambers trapezoidal, variable in width, increasing more in height than width as added, final chamber closed with an ellipsoidal cap. Pore frames on post abdominal chambers polygonal very gradually increasing in size distally. Slightly raised transverse ridges and/or slight alignment of pores on distal chambers observed on some specimens.

Original remarks: This species differs from Lantus praeobesus n. sp. in being less inflated distally and by sometimes possessing a few very rudimentary circumferential ridges between chambers. L. intermedius differs from L. sixi Yeh in lacking constrictions between post abdominal chambers. L. intermedius appears to be intermediate between L. praeobesuswhich first appears in the earliest Pliensbachian and L. sixi Yeh which appears later in the late Pliensbachian and Toarcian.

Etymology: From Latin: intermedius, -a, -um intermediate; adjective.

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 obesus, Lantus praeobesus, Lantus sixi, Lantus sutnal

Type specimen: GSC 111724. 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 (47: British Columbia collections), Japan (3)

Total: 50 collections each including a single occurrence

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Specimen images are retrieved through the ePANDDA API.


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