Terebratulina latifrons Dall, 1920

Rojas, Alexis, Gracia, Adriana & Patarroyo, Pedro, 2015, Brachiopods from off the San Bernardo Archipelago (Colombian Caribbean), with comments on specific synonymies in Tichosina Cooper, 1977, Zootaxa 3914 (1), pp. 55-63 : 58

Terebratulina latifrons Dall, 1920

( Figure 2 F–I)

1920 Terebratulina cailleti var. latifrons Dall , p. 309.

1977 Terebratulina latifrons Dall—Cooper , p. 100–102, pl. 17, figs 1–13. 1990 Terebratulina latifrons Dall—Logan , p. 129.

Occurrence. Off the San Bernardo Archipelago, Colombian Caribbean: MARCORAL station D35 (9° 54.010'N; 76° 10.162' W).

Material. One conjoined shell INV BRA 8.

Description. External characters: shell small (length 11.3 mm), subtriangular in outline, slightly longer than wide, maximum width anterior to midlength; beak suberect, foramen small in size; anterior commissure broadly uniplicate, lateral commissure slightly concave, ventral sulcus wide and developed in juvenile growth stage; surface fascicostellate, with slightly granulated ribs. Internal characters not observed.

Remarks. The single specimen available is consistent in outline, shape of anterior commissure, foramen size and fascicostellate ornamentation with Terebratulina latifrons Dall, 1920 . It corresponds to Cooper’s description and illustrations (pl. 17, figs. 1–12). However, the ventral sulcus in the Colombian material is slightly broader and the granulated surface indicated by Cooper as typical for the species is not observed or preserved. This taxon was originally described as a variety of T. cailleti by Dall (1920) based on its wider shell and more developed folding. Those features are present in our material. This species has been reported as rare in Barbados, Trinidad and Tobago, Costa Rica, Florida (Gerda stations 713, 982), Yucatan Channel (Gerda station 947), Guiana (Oregon station 2248), St. Vincent (Oregon station 5955), Caicos Island (Pillsbury station 1142), Pelican Island and Surinam ( Dall 1920; Copper 1977; Endo & Curry 1990; Logan 1990). It is also reported in the Guajira, Northern Caribbean of Colombia (Pillsbury station 769, Cooper 1977). The material studied consisted of a single dead specimen, with the external surface slightly abraded and discolored.

Figures

FIGURE 2. Brachiopods off the San Bernardo Archipelago, Colombian Caribbean. A – E. Tichosina plicata Cooper, 1977. A – D. INV BRA 5 conjoined shell. A. Dorsal view. B. Lateral view. C. Ventral view. D. Anterior view. E. INV BRA 6, inner view of dorsal valve showing the loop and broad transverse band. 2 F – I. Terebratulina latifrons Dall, 1920. INV BRA 8 conjoined shell. F. Dorsal view. G. Lateral view. H. Ventral view. I. Anterior view. 2 J – K. Terebratulina cailleti Crosse, 1865. INV BRA 9. J. Inner view of ventral valve. K. Inner view of dorsal valve showing the loop. L – Q. Argyrotheca barrettiana (Davidson, 1866). INV BRA 7. L. Conjoined shell, dorsal view. M. Lateral view. N. Ventral view. O. Anterior view. P. Oblique inner view of ventral valve showing the depressions near to the anterior end of the ventral septum. Q. Inner view of dorsal valve. P – Q. SEM photographs. All scales 5 mm.