PBDB Taxon

Basic info	Taxonomic history	Classification	Included Taxa
Morphology	Ecology and taphonomy	External Literature Search	Age range and collections

Simomactra

Bivalvia - Cardiida - Mactridae

Taxonomy

Simomactra was named by Dall (1894). It is extant.

It was assigned to Mactrinae by Coan et al. (2000), Moore (2003); and to Mactridae by Coan and Valentich-Scott (2012), Hickman (2015).

Species

S. dolabriformis, S. falcata, S. planulata

Synonyms

Symmorphomactra was named as a genus. It is extant.

It was reranked as Spisula (Symmorphomactra) by Packard (1916), Oldroyd (1925); it was synonymized subjectively with Simomactra by Coan et al. (2000).

It was assigned to Spisula by Packard (1916), Oldroyd (1925); and to Veneroida by Sepkoski (2002).

Synonymy list

Year	Name and author
1894	Simomactra Dall
1916	Spisula (Symmorphomactra) Packard p. 297
1925	Spisula (Symmorphomactra) Oldroyd p. 8
2000	Simomactra Coan et al. p. 458
2002	Symmorphomactra Sepkoski
2003	Simomactra Moore
2012	Simomactra Coan and Valentich-Scott p. 554
2015	Simomactra Hickman p. 32

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Rank	Name	Author
kingdom	Animalia	()
—	Bilateria
—	Eubilateria	Ax 1987
—	Protostomia
—	Spiralia
superphylum	Lophotrochozoa
phylum	Mollusca
class	Bivalvia
—	Eubivalvia
subclass	Autobranchia	(Groblen 1894)
infraclass	Heteroconchia	(Gray 1854)
—	Cardiomorphi	Ferussac 1822

Rank	Name	Author
—	Cardioni	Ferussac 1822
—	Cardiidia	Ferussac 1822
—	Cardiata	Ferussac 1822
superorder	Cardiiformii	Ferussac 1822
order	Cardiida	Ferussac 1822
suborder	Cardiidina	Ferussac 1822
—	Veneroidei	(Gray 1854)
—	Veneroitei	Gray 1854
superfamily	Mactroidea	(Lamarck 1809)
family	Mactridae	Lamarck 1809
genus	Simomactra	Dall 1894

If no rank is listed, the taxon is considered an unranked clade in modern classifications. Ranks may be repeated or presented in the wrong order because authors working on different parts of the classification may disagree about how to rank taxa.

G. Simomactra Dall 1894

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Simomactra dolabriformis Conrad 1867 [hatchet surfclam]

Simomactra falcata Gould 1850 [hooked surfclam]

†Simomactra falcata brioniana Trask 1922

Simomactra planulata Conrad 1837 [flat surfclam]

Invalid names: Symmorphomactra [synonym]

Diagnosis

Reference	Diagnosis
E. L. Packard 1916 (Spisula (Symmorphomactra))	Cardinals prominent, thin, posterior arm of the cardinal tooth overhangs the chondophore; accessories on each arm; hinge plate flat.

Measurements

No measurements are available

Composition:

aragonitec

Locomotion:

facultatively mobilef

Life habit:

infaunalf

Diet:

suspension feederf

Vision:

blindc

Created:

2009-09-09 13:48:47

Modified:

2009-09-09 15:48:47

Source: f = family, c = class

References: Sanchez Roig 1926, Aberhan et al. 2004

Age range

Maximum range based only on fossils: base of the Priabonian to the top of the Late/Upper Pleistocene or 37.71000 to 0.01170 Ma
Minimum age of oldest fossil (stem group age): 33.9 Ma

Collections (30 total)

Time interval	Ma	Country or state	Original ID and collection number
Priabonian	37.71 - 33.9	USA (Oregon)	S. sp. (40192)
Early/Lower Pliocene	5.333 - 3.6	USA (California)	Mactra dolabriformis (97240 97241 97404) Spisula falcata (220195)
Pliocene	5.333 - 2.58	USA (California)	Mactra falcata (96885)
Pleistocene	2.58 - 0.0117	USA (Oregon)	Spisula falcata (71142)
Pleistocene	2.58 - 0.0117	Mexico (Baja California)	Spisula dolabriformis (96592)
Quaternary	2.58 - 0.0	USA (California)	Spisula planulata (37938)
Middle Pleistocene	0.774 - 0.129	USA (California)	Mactra falcata (222663 222664) Spisula falcata (222998) Spisula planulata (138723)
Middle Pleistocene - Late/Upper Pleistocene	0.774 - 0.0117	USA (California)	Spisula planulata (223009)
Late/Upper Pleistocene	0.129 - 0.0117	USA (California)	Mactra falcata (222659 222660 222661 222662 226458 240609) Mactra planulata (59063 96895) Spisula dolabriformis (96566) Spisula falcata (219029 219030 240555 240636) Spisula falcata, Spisula planulata (160361) Spisula planulata (240661 240662)