Paratarrasius hibbardi Lund and Melton Jr. 1982

By oilshale (edited)

• December 29, 2016

Taxonomy

Kingdom: Animalia
Phylum: Chordata
Class: Actinopteri Cope, 1871
Order: Tarrasiiformes Berg, 1940
Family: Tarrasiidae Woodward, 1891
Genus: Paratarrasius
Species: Paratarrasius hibbardi
Author Citation Lund and Melton Jr. 1982

Geological Time Scale

Eon: Phanerozoic
Era: Paleozoic
Period: Carboniferous
Sub Period: Mississippian
Epoch: Late
International Age: Serpukhovian

Stratigraphy

Big Snowy Group
Heath Formation
Bear Gulch Bed

Provenance

Acquired by: Purchase/Trade

Dimensions

Length: 10 cm

Location

Bear Gulch
Fergus County
Montana
United States

• bear gulch
• fergus
• heath shale
• montana
• paratarrasius
• tff-oilshale-ch1179

Comments

Taxonomy from Lund & Poplin 2002.

Diagnosis for P. hibbardi from Lund & Melton 1982, p. 486: "Tarrasioid fishes ranging in length to 136 mm; the maximum head length/total length
ratio is 0.155; maximum body height total/length ratio is 0.172; the total length/snout-vent length ratio is 1.746. There are 27 to 29 precaudal vertebral arches and 68 to 73 precaudal scale rows. There are 28 to 31 scale rows above the lateral line at the anal notch and 50 to 54 rows below the
lateral line. There are 27 to 28 caudal vertebral arches, disappearing at the downturn of the tail, and 78 to 81 caudal scale rows. There are approximately 4 jointed, unbranched fin rays to each vertebral arch."

Line drawing from Lund & Melton 1982, p. 489: 

Identified by oilshale using Lund & Melton 1982.

References:

R. Lund and W. G. Melton Jr. 1982. A new actinopterygian fish from the Mississippian Bear Gulch limestone of Montana. Palaeontology 25(3):485-498.
R. Lund and C. Poplin 2002. Cladistic analysis of the relationships of the Tarrasiids (Lower Carboniferous Actinopterygians). Journal of Vertebrate Paleontology 22:480-486.