A new genus and species of a Middle Cambrian stem group brachiopod, Acanthotretella spinosa. Reconstruction of the shell of A. spinosa in lateral and dorsal views. The dorsal view is drawn so as to show internal features: the internal pedicle tube, the umbonal scar and the visceral cavity (from top to bottom). It is covered by long, slender spines that are posteriorly inclined at an oblique angle away from the anterior margin. Acanthotretella spinosa is unique from other Cambrian brachiopods due to the presence of spines.
Coyrighted material published in HOLMER, L. E., AND J. B. CARON. 2006. A spinose stem group brachiopod with pedicle from the Middle Cambrian Burgess Shale. Acta Zoologica, 87:273-290.
Pencil and carbon dust on paper
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