Key:  Family Yoldiidae

Phylum Mollusca
 Class Bivalvia
  Subclass Protobranchia
   Order Nuculida  (Paleotaxodonta)

Taken primarily from  Kozloff, 1987, 1996 p. 268 (Copyright 1987, 1996, University of Washington Press.  Used in this web page by permission of University of Washington Press)
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1a  Shell swollen, posterior end broadly truncate Yoldia (Megayoldia) thraciaeformis
1b Shell rather flat, not swollen; posterior end not truncate 2
2a Concentric sculpture not coinciding with growth lines (there are slight concentric ridges that cross the growth lines) (Y. scissurata in Kozloff key) Yoldia seminuda
2b Without any concentric sculpture other than growth lines 3
3a Umbones slightly posterior to the middle; length twice the height Yoldia (Yoldia) amygdalea
3b Umbones at the middle; length slightly less than twice the height Yoldia (Yoldia) myalis

Taxonomic Levels Represented in This Key:

  Yoldia (Yoldia) myalis
  Yoldia seminuda

Page created by Dave Cowles, 2006
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