PBDB Taxon

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

Isognomon (Isognomon) clarki

Bivalvia - Ostreida - Malleidae

Taxonomy

Pedalion clarki was named by Effinger (1938). Its type specimen is UCMP 33513 and is a 3D body fossil.

It was recombined as Isognomon (Isognomon) clarki by Squires (1989).

Sister species lacking formal opinion data

I. alatus, I. bathonicus, I. biplicatum, I. bouchardi, I. brentonensis, I. carolinensis, I. cereviciana, I. chavani, I. cornelliana, I. flambarti, I. flamberti, I. foliaceum, I. heberti, I. holmesi, I. igsognomoides, I. infraliassica, I. jupiter, I. karakuldjensis, I. lamberti, I. leona, I. lotenoensis, I. lugdunensis, I. lusitanicum, I. lusitanicus, I. marspiallis, I. maxillatus, I. maxilliata, I. maxilliatus, I. nanus, I. perplana, I. promytilodes, I. promytiloides, I. pseudotomiyasui, I. quadrisulcatus, I. rekohuenis, I. ricordeanus, I. ricordiana, I. rollei, I. rugosum, I. rugosus, I. sanchuensis, I. securiformis, I. subplana, I. subplanatum, I. subplanum, I. subspatulus, I. theseni, I. tomiyasui, I. tortum, I. trivale, I. valida, I. volaticum, I. woodsi, I. yinganensis, I. zelandica, I. inaequicrenata, I. maxillatus, I. choshiensis, I. flambarti, I. ichikawai, I. jupiter, I. mechanquilensis, I. mytiloides, I. promytiloides, I. pygmaea, I. rectangularis, I. rikuzenicus, I. sanchuensis, I. subplana, I. volaticum, I. mimeticus, I. ageroensis, I. bathonicus, I. murchisonii, I. patchamensis, I. thurmanni, Pedalion linguaeformis

Synonymy list

Year	Name and author
1938	Pedalion clarki Effinger pp. 367 - 368 figs. Plate 45, figures 9, 10
1989	Isognomon (Isognomon) clarki Squires p. 279 figs. Figure 2.1 - 2.4

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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	Pteriomorphia	(Beurlen 1944)
—	Ostreomorphi	Ferussac 1822

Rank	Name	Author
—	Ostreioni	Ferussac 1822
—	Ostreata	Ferussac 1822
superorder	Ostreiformii	Ferussac 1822
order	Ostreida	(Fërussac 1822)
suborder	Malleidina	Gray 1854
superfamily	Pterioidea	Gray 1847
family	Malleidae	Lamarck 1819
subfamily	Isognomoninae	(Woodring 1925)
genus	Isognomon	Lightfoot 1786
subgenus	Isognomon	Lightfoot 1786
species	clarki	()

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.

†Isognomon (Isognomon) clarki Effinger 1938

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Diagnosis

No diagnoses are available

Measurements

No measurements are available

Composition:

aragonitef

Composition 2:

low Mg calcitef

Environment:

marine, brackisho

Locomotion:

stationaryg

Attached:

yesg

Epibiont:

yessuperf

Life habit:

epifaunalg

Diet:

suspension feederg

Vision:

blindc

Created:

2009-04-13 11:22:47

Modified:

2025-04-24 13:29:46

Source: g = genus, f = family, superf = superfamily, o = order, c = class

References: Kiessling 2004, Sanchez Roig 1926, Aberhan et al. 2004, Hendy et al. 2009

Age range: base of the Bartonian to the top of the Priabonian or 41.03000 to 33.90000 Ma

Collections (8 total)

Time interval	Ma	Country or state	Original ID and collection number
Middle Eocene	48.07 - 37.71	USA (California)	Isognomon clarki (202071 202081 202083 202084)
Bartonian	41.03 - 37.71	USA (Washington)	Isognomon clarki (161922)
Bartonian	41.03 - 37.71	USA (California)	Isognomon clarki (52804)
Priabonian	37.71 - 33.9	USA (Washington)	Pedalion clarki (40733)
Priabonian	37.71 - 33.9	USA (Oregon)	Isognomon clarki (193975)