Fossil Birds of the Oreana Local Fauna (Blancan), Owyhee County, Idaho
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Great Basin Naturalist Volume 46 Number 4 Article 22 10-31-1986 Fossil birds of the Oreana local fauna (Blancan), Owyhee County, Idaho Jonathan J. Becker University of Florida, Gainesville, Florida Follow this and additional works at: https://scholarsarchive.byu.edu/gbn Recommended Citation Becker, Jonathan J. (1986) "Fossil birds of the Oreana local fauna (Blancan), Owyhee County, Idaho," Great Basin Naturalist: Vol. 46 : No. 4 , Article 22. Available at: https://scholarsarchive.byu.edu/gbn/vol46/iss4/22 This Article is brought to you for free and open access by the Western North American Naturalist Publications at BYU ScholarsArchive. It has been accepted for inclusion in Great Basin Naturalist by an authorized editor of BYU ScholarsArchive. For more information, please contact [email protected], [email protected]. — FOSSIL BIRDS OF THE OREANA LOCAL FAUNA (BLANCAN), OWYHEE COUNTY, IDAHO Jonathan J. Becker Abstract. —The Oreana local fauna (Blancan) occurs in exposures of the Glenns Ferry Formation in Owyhee County, Idaho. Fossil birds present include Phalacrocorax cf. P. idahensis, Pelecanus cf. P. halieus, an indeterminate anatid, an indeterminate falconid, two species oiOtus, and a species oiColaptes larger than modern C. auratus that provides the earliest record of a colaptine woodpecker. = The Oreana local fauna is a Blancan ( ontology collections of the IMNH. Pliocene) assemblage of vertebrate fossils Measurements were made with Kanon dial from two localities in southwestern Idaho near calipers, accurate to 0.05 mm and rounded to the town of Oreana, Owyhee County (IMNH the nearest 0.1 mm. BMDP statistical soft- 74001 in Sec 25 and IMNH 74004 (=^IMNH ware program BMDPID was used to calculate 78031) in Sec 1, T4S, RIW; 43 degrees 02' N simple descriptive statistics (Dixon 1981). 24' Lat. , 116 degrees W Long. , Oreana Quad- Computations were made at the Northeast rangle, U.S. Geologic Survey 7.5 minute se- Regional Data Center (NERDC) at the Uni- ries topographical map, 1949). Fossils from versity of Florida, Gainesville. Anatomical both localities come from exposures of the terminology follows Baumel et al. (1979). Glenns Ferry Formation (Malde et al. 1963) (= Oreana Formation of Anderson 1965) and Systematic Paleontology correlate with the Hagerman local fauna, ap- Order Pelecaniformes Sharpe, 1891 proximately 75 miles to the east (Conrad Family Phalacrocoracidae (Bonaparte, 1853) 1980). Smith et al. (1982) discuss the bio- Genus Phalacrocorax Brisson, 1760 stratigraphy of fishes in this formation. Phalacrocorax ci P. idahensis {Mdrsh, 1870) IMNH 74001 has produced many thou- sands of complete, disarticulated skeletal ele- Material —IMNH 74001/26527, complete ments of fish, along with a few mammal and left carpometacarpus; IMNH 74004/30221, bird remains from thick lenses of fine sand proximal end of left ulna; 74004/30223, proxi- interbedded with clays. This locality possibly mal end of right ulna. Tentatively referred. represents a shoreline with swash accumula- 74004/30224, partial upper mandible; 74004/ tions (Schaeffer 1972). Vertebrate fossil re- 30222, proximal end of left ulna; 74001/30217, mains are much more rare from IMNH 74004. right scapula. More detailed information on each locality is Remarks. —Although originally described available from IMNH upon request. from the Hemphillian Chalk Hills Formation (Marsh 1870), this species is better known from the Blancan Hagerman local fauna (Wet- Materials and Methods more 1933, Brodkorb 1958, Murray 1970). Comparative material of modern species The referred upper mandible is short and examined is in collections of the American heavy, having a concave dorsal surface, char- Museum of Natural History (AMNH), the acteristic of the subgenus Phalacrocorax Idaho Museum of Natural History (IMNH), (Howard 1946). The ulnae are within the Pierce Brodkorb (PB), and the National Mu- range of P. idahensis or are slightly larger seum of Natural History, Smithsonian Institu- (Murray 1970). tion (USNM). All fossil specimens from the The complete carpometacarpus is larger Oreana local fauna are in the vertebrate pale- than any reported by Murray (1970), eliminat- Department of Zoology, University of Florida, Gainesville Florida 326U. Present address: Division of Birds, National Museum of Natural History, Smithsonian Institution, Washington, DC. 20560. 763 764 Great Basin Naturalist Vol. 46, No. 4 deviation Table 1. Measurements of humeri ofOtus asio . Data are mean ± standard (number) and observed range. Measurements are TWSHAFT, transverse width humeral shaft; DSHAFT, depth of humeral shaft; TWDIST trans- verse width of distal end of humerus; DDIST, depth of distal end of humerus. , . October 1986 BECKER: Idaho Fossil Birds 765 asio from the Hagerman local fauna. The Din-opium, and some species o{ Picoides); (6) above specimen may represent the same spe- interorbital constriction narrow (similar to cies. Celeus and Veniliornis ; wide in Campephilus, Dendrocopus, and Sphyrapicus; intermedi- Otus sp. (Kaup, 1852) ate in other genera examined); (7) narrow Material.—IMNH 74001/30216, nearly width between nares (similar to Melanerpes complete right tarsometatarsus with caudal and Dinopium, wide in Sphyrapicus, Den- portion of trochlea IV missing. drocopus, Picoides, Veniliornis, Camp- Description. —Similar in morphology to ephilus, and Chrysocolaptes ; intermediate in female O. flammeolus (USNM 554125) but other genera examined); (8) basisphenoid re- much smaller (skeletons of males of O. gion inflated (not inflated in Veniliornis, Dry- flammeolus unavailable). Caudal projection of ocopus, Ca^npephilus, or Chrysocolaptes , in- process on trochlea II more developed in fos- flated in other genera examined); and (9) otic sil. Calcaneal ridge not as inclined laterally. region inflated (not inflated in Veniliornis, Remarks. —The paucity of skeletons of Campephilus or Chrysocolaptes); inflated to modern species of small owls makes it impos- slightly inflated in other genera. sible to determine the exact systematic rela- Colaptes sp. tionships of this fossil specimen. Material.—IMNH 74001/30218, cranium Order Piciformes (Meyer and Wolf, 1810) lacking entire upper jaw, pterygoids, and Suborder Pici Meyer and Wolf, 1810 quadrates. Family Picidae Vigors, 1825 Description.—IMNH 30218 is distin- Subfamily Picinae (Vigors, 1825) guished from Colaptes auratus and C. Tribe Colaptini melanochloros by larger size; from C. campes- Genus Colaptes Vigors, 1826 tris by having a more developed postorbital Generic diagnosis. —The skull of Co- process and a deeper, well-defined temporal laptes may be distinguished from other gen- fossa; from C. pitius by having a more bulbous era of New World Picinae by the following prominentia cerebellaris and a more caudo- combination of characters: (1) Interorbital rostrally oriented temporal fossa; and from C. septum completely ossified (similar to Sphy- rupicola by being smaller and having more rapicus, Campethera, Piculus, Celeus, and distinct hyoid grooves. Colaptes { = Neso- all Dinopium ; incompletely ossified or perforate celeus) fernandinae is very distinct from in Xiphidiopicus, Dendrocopus, Picoides, Ve- other species of Colaptes . In this species the niliornis, Dryocopus, Campe-philus, Picus, dorsum of the skull is dimpled, hyoid grooves and Chrysocolaptes ; variable in species of deep, prominentia cerebellaris poorly devel- Melanerpes); (2) dorsal surface of brain case oped, and the nuchal crest is well developed. slightly dimpled (heavily dimpled in Dryoco- See Table 2 for measurements. pus, Campephilus, Picus, and Chrysoco- Remarks. —North American Neogene laptes; smooth in Melanerpes, Sphyrapicus woodpeckers include Palaeonerpes shorti and Xiphidiopicus, slightly dimpled in other Cracraft and Morony 1969, based on a single genera examined); (3) supraorbital ridge distal end of a tibiotarsus from deposits equiv- present (absent to slightly developed in alent to the upper part of the Valentine For- Melanerpes, Campethera, Dendrocopus, Pi- mation (early Clarendonian). Cracraft and cus, and Dinopium; present in other genera Morony (1969) suggest that the affinities of examined); (4) groove for hyoids present (simi- Palaeonerpes are likely to be with the lar to Campethera, Piculus, Dryocopus, melanerpine woodpeckers rather than with Campephilus, Picus, and Dinopium; absent to genera such as Dendrocopos, Dryocopus, or slightly developed in other genera examined); Colaptes (5) fi-ontals flat to concave (similar to Melaner- Pliopicus brodkorbi Feduccia and Wilson pes, Piculus, Celeus, Dryocopus, Camp- 1967, based on a single distal tarsometatarsus, Wa- ephilus, and Chrysocolaptes ; inflated and ex- is from the mid- to late Clarendonian panded to varying degrees in other genera keeney local fauna (late Miocene) from the examined, producing a distinct, midsagittal Ogallala Formation, Kansas. Feduccia and crest in Xiphidiopicus, Campethera, Picus, Wilson (1967) consider Pliopicus to be allied 766 Great Basin Naturalist Vol. 46, No. 4 Table 2. Measurements of the crania of species oiColaptes. Data are mean, standard deviation, number measured, the caudal portion of the supraoccipital (Prominentia cerebellaris and observed range. LENGTH, greatest length from ) to the nasofrontal suture, measured on the midsagittal plane (Planum medianum), DEPTH, depth of skull from dorsal groove for the hyoid to the slight, anterioposteriorly oriented groove in the basitemporal, measured on the midsagittal plane; WIDTH, greatest transverse width brain case; W-TEMPORAL,