Skip to Main Content

Acrosterigma dalli

Geological Range

Late Pliocene to Early Pleistocene; Extinct.

Paleogeographic Distribution

Southern Florida.

Remarks

Original Description (from Heilprin, 1886, p. 131-132):

"Shell ovately elevated, moderately ventricose, with the beaks apical, touching (or nearly so), and directed slightly backwards; ribs about 30 to 33, smooth, moderately elevated, teretely rounded, with narrow, impressed interspaces; the ribs on the posterior slope narrower and more crowded than over the general surface, minutely echinated in part.

Hinge-line narrow, acutely curved, with prominent lateral teeth; a prominent triangular cardinal tooth in each valve. Height, from apex to basal margin, 5.3 inches; length (width), 3.7 inches."

Stratigraphic Occurrences

Early Pleistocene
Caloosahatchee Formation (S. FL)
Late Pliocene
Tamiami Formation (Pinecrest Beds) (S. FL)
<i>Acrosterigma dalli</i> from the Late Pliocene Tamiami Fm. (Pinecrest Beds) of Sarasota County, Florida (UF 135923).
Acrosterigma dalli from the Late Pliocene Tamiami Fm. (Pinecrest Beds) of Sarasota County, Florida (UF 135923).
Specimen of <i>Acrosterigma dalli</i> figured by Heilprin (1886, pl. , fig. 70); 5.3 in. in length.
Specimen of Acrosterigma dalli figured by Heilprin (1886, pl. , fig. 70); 5.3 in. in length.
Early Pleistocene Map
Early Pleistocene Map
Late Pliocene Map
Late Pliocene Map