Amia pattersoni GRANDE & BEMIS, 1998

Taxonomy

Bowfin

Kingdom: Animalia
Phylum: Chordata Haeckel 1874
Class: Actinopteri Cope 1871
Order: Amiiformes Hay 1929
Family: Amiidae Bonaparte, 1838
Genus: Amia
Species: Amia pattersoni
Author Citation GRANDE & BEMIS, 1998

Geological Time Scale

Eon: Phanerozoic
Era: Cenozoic
Period: Paleogene
Sub Period: None
Epoch: Eocene
International Age: Ypresian

Stratigraphy

Green River Formation
Fossil Butte Member

Provenance

Acquired by: Purchase/Trade

Dimensions

Length: 20 cm

Location

Warfield Quarry
Kemmerer
Wyoming
United States

• bowfin
• eocene
• green river
• tff-oilshale-ch1340
• warfield
• wyoming

Comments

Taxonomy from Grande & Bemis 1998.
Species diagnosis from Grande & Bemis 1998, p. 189:" Amia pattersoni sp. nov. differs from all other known amiine species in the following adult characters A through H. (A) The number of subinfraorbitals (four or more) is higher than in any other amiid. (B) The gular is longer and narrower than known in any other species of Amiinae. The center of ossification of the gular lies within the posterior half of the bone (indicated by ornamentation pattern) unlike †A. "robusta" where it lies in the middle of the bone. (C) The frontals are narrower than in any other species of Amiinae (width-to-length ratio = 0.31-0.36, Table 41, compared to 0.47-0.65 in A. calva, Table 2; 0.43-0.49 in †A. scutata, Table 21; 0.36-0.37 in † "A." hesperia, Table 31; and 0.40-0.55 in †Cyclurus, Tables 50, 60, 70, and text). (D) Mandible is longer than known for any other species of Amiinae (mandible as 7322 percent of head length is 69%-71%, Table 40, compared to 56%-68% for A. calva, Table 1; 59%-66% for †A. scutata, Table 20; 62% for t "A." hesperia, Table 30; and 51%-65% for †Cyclurus, Tables 50, 60, 70, and text). (E) Number of dorsal fin rays and radials differs from that of any other known Amia (45-47 segmented rays and 44-48 proximal radials, Table 48, compared to 48-51 segmented rays and 49-52 proximal radials for A. calva, Table 16; 51-53 segmented rays and 51-54 proximal radials for †A. scutata, Table 28; and est. 40 segmented rays and 39 proximal radials in † "A." hesperia, Table 38). (F) Fewer abdominal centra are present than in any other species of Amia (30-33, Table 45, compared to 38-40 in A. calva, Table 11; 33-34 in †A. scutata, Table 25; 32 in † "A." hesperia, Table 35). (G) The absence of the lacrimal notch. This notch (for articulation with the first subinfraorbital) is usually present in all other species of Amia. (H) The posterior margin of the opercle is sigmoidal, bulging convexly along the lower half and slightly concave along the upper half, unlike all amiines except for †A. "robusta". Characters B, C, and D above are correlated with an elongated skull in this species."

Line drawing from Grande and Bemis 2002, p. 186;

References:
L. Grande: An updated review of the fish faunas from the Green River Formation, the world's most productive freshwater Lagerstaetten. In Eocene biodiversity., unusual occurrences and rarely sampled habitats. Gunell, Gregg F., eds, Topics in Geobiology, Vol 18, p. 1-38.
Lance Grande & William E. Bemis (1998) A Comprehensive Phylogenetic Study of Amiid Fishes (Amiidae) Based on Comparative Skeletal Anatomy. an Empirical Search for Interconnected Patterns of Natural History, Journal of Vertebrate Paleontology, 18:S1,1-696, DOI: 10.1080/02724634.1998.10011114