Search the Community

Collected South of the Radar Dome near the cliff face.

Collected South of the Radar Dome near the cliff face.

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

Astephus and Hypsidoris are both members of the Family Ictaluridae, native to North America. Green River catfish are easily recognized by their stout dorsal and pectoral spines, scale less bodies and broad skull. Ictalurid species have four pairs of barbels (or whiskers). Like modern catfish, they possessed a vibration sensitive organ called the Weberian apparatus. The Weberian apparatus consists out of specialized vertebrae at the front of the spinal column which passed vibrations to the inner ear using the swim bladder as a resonance chamber. The structure essentially acts as an amplifier of sound waves that would otherwise be only slightly perceivable by the inner ear structure alone. Normal size of Astephus is around 15cm and rarely exceeds 18cm, maximum total length is about 30cm. Hypsidoris seems to be in the same size range. The easiest way to distinguish Hypsidoris from Astephus is by counting anal fin rays; H. farsonensis has about 15 to 17 and A. antiquus has about 26. The diet of Green River catfish was probably similar to existing ictalurids consisting of plants, small fish, crayfish and mollusks. Astephus and Hypsidoris were probably bottom feeders. Astephus antiquus is unknown as a body fossil in the middle unit of Fossil Butte Member, and only one specimen has been found in all of Fossil Lake, although it is abundant in Lake Gosiute strata. The discovery of numerous and widespread fossil catfish in oil shale units of the Laney Member of the Eocene Green River Formation is evidence of aerobic conditions in the hypolimnic waters of ancient Lake Gosiute. Hypsidoris farsonensis has only been found in Lake Gosiute deposits of the Green River Formation, east of Fossil Lake. Revised Species Diagnosis from Grande & Lundberg 1988, p. 146: "An extinct genus of ictalurid catfish that differs from all other known ictalurids by the following combination of characters: lack of jawmuscle origin on the temporal region of the skull roof, the possession of villiform vomerine teeth, the possession of tooth plates lateral to the vomerine tooth plate, and the location of the cranial opening for the infraorbital canal in the sphenotic rather than the frontal. Admittedly none of these characters alone is unique to †Astephus, but the combination of all of them is. The genus appears to be unique among catfishes in having the ventral surface of the supraethmoid inclined sharply upward relative to the ventral surface of the vomer. No other characters apparently unique to the genus were discovered here." Emended Species Diagnosis from Grande & Lundberg 1988, p. 147: "A species that differs from the only other known species recognized here (tA. antiquus) by the presence of a narrower vomerine tooth patch. Also, the median supraethmoid cleft appears to be deeper and the cranial fontanelles appear to be wider than in †A. antiquus (although the latter feature is possibly an artifact of preservation)." Line drawing from Grande & Lundberg 1988, p. 151: Identified by oilshale. References: Grande, L. and J. G. Lundberg. 1988. Revision and redescription of the genus Astephus (Siluriformes: Ictaluridae) with a discussion of its phylogenetic relationships. J. Vert. Paleont 8:139–171 Grande, L. 1987. Redescription of Hypsidoris farsonensis (Teleostei: Siluriformes), with a reassessment of its phylogenetic relationships. Journal of Vertebrate Paleontology 7:24–54. Grande, L. and M. C. C. de Pinna. 1998. Description of a second species of the catfish Hypsidoris and a reevaluation of the genus and the family Hypsidoridae. Journal of Vertebrate Paleontology 18:451–474.

Astephus and Hypsidoris are both members of the Family Ictaluridae, native to North America. Green River catfish are easily recognized by their stout dorsal and pectoral spines, scale less bodies and broad skull. Ictalurid species have four pairs of barbels (or whiskers). Like modern catfish, they possessed a vibration sensitive organ called the Weberian apparatus. The Weberian apparatus consists out of specialized vertebrae at the front of the spinal column which passed vibrations to the inner ear using the swim bladder as a resonance chamber. The structure essentially acts as an amplifier of sound waves that would otherwise be only slightly perceivable by the inner ear structure alone. Normal size of Astephus is around 15cm and rarely exceeds 18cm, maximum total length is about 30cm. Hypsidoris seems to be in the same size range. The easiest way to distinguish Hypsidoris from Astephus is by counting anal fin rays; H. farsonensis has about 15 to 17 whereas A. antiquus has about 26. The diet of Green River catfish was probably similar to existing ictalurids consisting of plants, small fish, crayfish and mollusks. Astephus and Hypsidoris were probably bottom feeders. Astephus antiquus is unknown as a body fossil in the middle unit of Fossil Butte Member, and only one specimen has been found in all of Fossil Lake, although it is abundant in Lake Gosiute strata. The discovery of numerous and widespread fossil catfish in oil shale units of the Laney Member of the Eocene Green River Formation is evidence of aerobic conditions in the hypolimnic waters of ancient Lake Gosiute. Hypsidoris farsonensis has only been found in Lake Gosiute deposits of the Green River Formation, east of Fossil Lake. Taxonomy from Grande 1987. Family Diagnosis from Grande 1987, p. 28: "A family of catfishes that differs from all other known catfishes by the following combination of characters. Unlike all families (at least primitively) but Diplomystidae, †hypsidorids have a maxilla that bears many close-set conical teeth (the teeth are essentially the same shape and size as those observed here in Diplomystes; a relatively large maxilla that is expanded distally and has a long mesially directed ventral palatine condyle (maxilla not reduced in size or thin and rod-like as in most living catfishes); and a palatine that is flattened anteriorly, where it is greatly expanded to form two condyles for the maxilla (vs. a relatively simple rod-like shape without a broad anterior end as in most other catfishes). Unlike Diplomystidae, †Hypsidoridae have a single suprapreopercle (Diplomystes has 2); six infraorbital bones (Diplomystes has at least 9); a principal caudal fin-ray count of 8/9 (Diplomystes has 9/9); and a posterior extension of lamellar bone over the ventral surface of the fifth and sixth centra from more anterior vertebrae (Diplomystes has no such bone). The shape of the lower jaw in †H. farsonensis appears to be unique among Siluriformes. It has an extremely high coronoid process that is higher than in any other catfish observed here that also has a long dentary (Trogloglanis also has an extremely high coronoid process, but the dentary is very short: see Fig. 8)." Emended Species Diagnosis from Grande 1987, p. 28: "Same as for family (monotypic). The original description included a particular range of pectoral and dorsal spine length measurements as a diagnostic character, but based on additional material this is more variable within the species than previously recorded by Lundberg and Case (1970:452) and Grande (1984:116). See text for further explanation." Line drawing from Grande 1987, p. 29: Identified by oilshale. References: Grande, L. and J. G. Lundberg. 1988. Revision and redescription of the genus Astephus (Siluriformes: Ictaluridae) with a discussion of its phylogenetic relationships. J. Vert. Paleont 8:139–171. Grande, L. 1987. Redescription of Hypsidoris farsonensis (Teleostei: Siluriformes), with a reassessment of its phylogenetic relationships. Journal of Vertebrate Paleontology 7:24–54. Grande, L. and M. C. C. de Pinna. 1998. Description of a second species of the catfish Hypsidoris and a reevaluation of the genus and the family Hypsidoridae. Journal of Vertebrate Paleontology 18:451–474.

Juvenile Phareodus

Detail of skull and teeth of juvenile Phareodus specimen that I collected at Carl Ulrich Quarry back in the early '70s when he used to let visitors collect with him.

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.