- Arcoida
Taxobox
name = Arcoida
fossil_range = LowerOrdovician to Recent
image_caption = "Arca zebra " shell
regnum =Animal ia
phylum =Mollusca
classis =Bivalvia
subclassis =Pteriomorpha
ordo = Arcoida
subdivision_ranks = Families
subdivision = See text.The Arcoida is an
extant order of clams orbivalve mollusc s. This order dates back to the lowerOrdovician period.Seven families are currently recognised within the order, including the well-known
ark clam s or ark shells in the familyArcidae .uperfamilies and families in the order Arcoida
* Superfamily
Arcoidea
** Arcidae
** Cucullaeidae
**Noetiidae
**Parallelodontidae
* SuperfamilyLimopsoidea
**Glycymerididae
**Limopsidae
**Philobryidae References
Wikimedia Foundation. 2010.