Search results
Results from the WOW.Com Content Network
Sand dollars diverged from the other irregular echinoids, namely the cassiduloids, during the early Jurassic, [5] with the first true sand dollar genus, Togocyamus, arising during the Paleocene. Soon after Togocyamus, more modern-looking groups emerged during the Eocene. [1] Sand dollars are small in size, averaging from 80 to 100 mm (3 to 4 ...
Like other sand dollars, Leodia sexiesperforata is radially symmetrical and flattened dorso-ventrally, having a circular or semi-pentagonal shape, but it also displays secondary, front-to-back bilateral symmetry. It is usually somewhere between 4.8 and 14.5 cm (1.9 and 5.7 in) in diameter.
Heliophora orbicularis, also known as the West African Sand Dollar, is a small sand dollar in to the family Rotulidae, and the only species in the genus Heliophora. It, and other members of Rotulidae have been found in West African marine strata from the Late Miocene onward. Like the related Rotula , it is still extant.
Rotulidae is a family of small sand dollars native to the Atlantic coast of Africa, with 3 genera, with Rotula and Heliophora being extant, the other, Rotuloidea, being extinct since the Pliocene, but all three being found in the fossil record along the Atlantic African coast since the Miocene.
Get AOL Mail for FREE! Manage your email like never before with travel, photo & document views. Personalize your inbox with themes & tabs. You've Got Mail!
Keyhole sand dollar refers to five living species of sand dollars in the genus Mellita, plus the extinct †Mellita aclinensis.They are found on the Atlantic coasts of the Americas, ranging across the Caribbean Islands (e.g. Bermuda, Jamaica and Puerto Rico), from the southern United States at the north, to the southeastern coast of Brazil at the south.
Upgrade to a faster, more secure version of a supported browser. It's free and it only takes a few moments:
Clypeasteridae is a family of sea urchins in the order Clypeasteroida.This family was first scientifically described in 1835 by the Swiss-American biologist Louis Agassiz.. The clypeasteridae also known as the sand dollar, are round and semi-flat organisms with spines lining the underside of the body and elongated genital papillae aiding its survival and reproduction.