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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

Juvenile Phareodus

This juvenile stingray is an Asterotrygon . The body is covered with denticles and the tail is thicker than that of a normal Heliobatis. References: M. De Carvalho, J. Maisey, L. Grande (2004): Freshwater Stingrays of the Green River Formation of Wyoming with the Description of a new Genus. Bulletin of the American Museum of Natural History, Number 284, 136pp., 53 figures, 7 tables.

Amphiplaga is one of the rarer of the Green River fish fossils, making up some 1% of the total from Fossil Lake, its only known location. Amphiplaga belongs to the family Percopsidae within the order Percopsiformes. The Order Percopsiformes is a small order of North American freshwater fishes that includes three families: Amblyopsidae (cavefishes); Aphredoderidae (pirate perches); and Percopsidae (trout-perches). Closely related to neither trout nor perch, trout-perches have characteristics of both the trout and perch families. They exhibit characters of the salmonids, such as an adipose fin, cycloid scales, and soft fin rays, as well as characters of the percids, such as dorsal and anal fin spines, and ctenoid scales. Trout-perch are generally silvery in appearance, often with a partially transparent appearance, and relatively large heads and eyes. They are small fish with weak fin spines, and an adipose fin similar to those of trouts. Amphiplaga grew to as much as 150 mm. long; the average length was 100 mm. They feed on insects and small crustaceans. Fossil percopsids are only known from North America, the current home of the extant genus Percopsis. References: Grande, L. (1984): PALEONTOLOGY OF THE GREEN RIVER FORMATION, WITH A REVIEW OF THE FISH FAUNA. THE GEOLOGICAL SURVEY OF WYOMING, BULLETIN 63