Acanthodes "beecheri" Eastman 1902

By oilshale

• July 12

Taxonomy

Kingdom: Animalia
Phylum: Chordata Haeckel 1874
Class: Acanthodii Owen 1846
Order: Acanthodida Berg 1940
Family: Acanthodidae Huxley 1861
Genus: Acanthodes
Species: Acanthodes "beecheri"
Author Citation Eastman 1902

Geological Time Scale

Eon: Phanerozoic
Era: Paleozoic
Period: Carboniferous
Sub Period: Pennsylvanian
Epoch: Middle
International Age: Moscovian

Stratigraphy

Kewanee Group
Carbondale Formation

Provenance

Acquired by: Purchase/Trade

Dimensions

Length: 4.5 cm

Location

Pit 11
Mazon Creek
Illinois
United States

• carbondale formation
• carboniferous
• illinois
• mazon creek
• pennsylvian
• pit11
• TFF-oilshale-Ch602

Comments

Acanthodes "beecheri" is a problematic species because the preservation is inadequate and they are probably juvenile fish.

Gregory (1951) concluded that the scaleless A. beecheri specimens are immature and possibly represent the young of A. marshi Eastman 1902.
Characterization by Eastman 1905, p. 537: "A very small species, attaining an extreme length of about 5.5cm. Body elongated and slender, the maximum depth being contained about nine times in the total length. Pectoral spines not much stouter or longer than the others; pelvic fins small, slightly nearer the pectorals than the anal; anal fin slightly larger than the dorsal, which is placed immediately behind. Length of dorsal and anal spines greater than maximum depth of the trunk. Caudal lobe remarkably elongate. Scales very minute."

Line drawing by Eastman 1905, p. 537:

References;
Eastman, C. R. (1902) Some Carboniferous cestraciont and acanthodian sharks: Harvard Univ., Mus. Compar. Zoology, Bull., v. 39, n. 3, p. 55- 99.
Eastman, C.R. (1905) The Carboniferous Fish-Fauna of Mazon Creek, Illinois: Journal of Geology, 10(5), 535–541.
Gregory, J. T. (1951) A new specimen of Acanthodes marshi: Southern California Acad. Sci., Bull., v. 50, Pt. 1, p. 21-24.
Zidek , J .  (1976 ) Kansas Hamilton Quarry (Upper Pennsylvanian) Acanthodes, with remarks on the previously reported North American occurences of the genus .— Univ . Kansas Paleont . Contr ., 83 : 1 - 41 , Lawrence .