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Spiniferites ancoriferus ssp. ancoriferus

Spiniferites ancoriferus ssp. ancoriferus

Autonym
Holotype: Cookson and Eisenack, 1974, pl.21, fig.4
Age: Middle-Late Cretaceous

Original diagnosis: Cookson and Eisenack, 1974, p.58
Shell spherical to oval, provided with relatively short processes, which are generally only slightly furcated, and with more or less developed "spanning-membranes". Girdle more or less distinct. However, the processes which arise from the girdle-lists and in particular the ones in the saggital-plane, are especially sturdily developed and are bent away from one another in apical and antapical direction, so that - in conjunction with the ""spanning-membranes" which are here especially highly developed - anchor-shaped protuberances are formed (in the type-specimen only on the left-hand side, in the "paratypoid" on both sides, though to a lesser degree on the right-hand side). The "spanning-membranes" tower above the apex in form of a "slit-up" triangle and can also be spread over the antapex (in the case of the type-specimen) in lamellae-like manner.
Dimensions: Type-specimen: shell about 42 x 42 µm, overall about 78 x 62 µm. "Paratypoid": shell about 42 x 38 µm overall about 67 x 52 µm.

Occurrence: Type: Madura No. 1 bore at 1073-1104 ft. Paratypoid: Ginging Brook bore, at 404-414 ft.

Remarks: Cookson and Eisenack, 1974, p.58
The differences between type and paratypoid are to be attributed to variability.
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