[1] It contains several major orders, including the Arcida, Ostreida, Pectinida, Limida, Mytilida, and Pteriida.
Pteriomorphian bivalves possess five types of photoreceptors, each evolving independently and each associated with different clades within Pteriomorphia.
[4] As such, pteriomorphia respond to the presence of a shadow by retracting their siphon, adduction, digging, or some combination of the three.
[6] The cladogram is based on molecular phylogeny using mitochondrial (12S, 16S) and nuclear (18S, 28S, and H3) gene markers by Yaron Malkowsky and Annette Klussmann-Kolb in 2012.
[7] Palliolinae (in part) Palliolinae (in part) and Camptonectinae Chlamydinae (70 mya) Pecten Flexopecten (247 mya) Aequipecten Limidae (file shells) other Pteriomorphia (oysters, mussels) In 2010 a new proposed classification system for the Bivalvia was published by Bieler, Carter & Coan revising the classification of the Bivalvia, including the subclass Pteriomorphia.