The Rotaformidae, a New Family of Upper Cretaceous Nassellariina (Radiolaria) from the Great Valley Sequence, California Coast Ranges
The Rotaformidae, a New Family of Upper Cretaceous Nassellariina (Radiolaria) from the Great Valley Sequence, California Coast Ranges

Author: Emile A. Pessagno (Jr.)

Publisher:

Published: 1970

Total Pages: 0

ISBN-13:

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The Rotaformidae Pessagno, n. fam., are a bizarre group of dicyrtid Nassellariina with cartwheel-shaped tests and nine cephalic skeletal elements identical to those of the Neosciadiocapsidae Pessagno. It is postulated that the Neosciadiocapsidae gave rise to the Rotaformidae through (1) the rotation of the cephalis and upper thorax into the plane of the thoracic skirt and (2) the loss of the thoracic skirt and the subsequent development of a thoracic ring. Two new genera and seven new species of Rotaformidae are described from the Upper Cretaceous portion of the Great Valley Sequence, California Coast Ranges.