Bonasa umbellus (Linnaeus, 1766)

James, Helen F., 2020, The Irvingtonian Avifauna of Cumberland Bone Cave, Maryland, Zootaxa 4772 (1), pp. 111-131 : 116

Bonasa umbellus

Material. USNM PAL 641979 , l tarsometatarsus: shaft lacking the trochleae and proximal articular surfaces, collected by Trent Spielman, probably on October 2, 1996 ( Fig. 1I ) .

USNM PAL 769092, l tarsometatarsus: shaft lacking most of the plantar surface, collected by Trent Spielman in the 1990s.

Description. All of the fossils of Tetraoninae from Cumberland Bone Cave fall within or close to the size range of modern B. umbellus . Among New World Tetraoninae , Bonasa umbellus is much larger than Lagopus leucura but considerably smaller than all others except Falcipennis canadensis , Lagopus lagopus , and L. muta . Bonasa differs from Lagopus and Falcipennis in having a proportionately long and slender tarsometatarsus. The two tarsometatarsi listed above are referable to B. umbellus on that basis. Note that USNM PAL 641979 appears to be from a full adult and is large compared with some B. umbellus skeletons, but is a good match for USNM BIRDS 641459, a male from Alberta, Canada.

Remarks. See below.

Figures

FIGURE 1. Fossils from Cumberland Bone Cave compared with modern taxa.A) fossil left humerus of Meleagris sp., USNM PAL 641969, caudal aspect; B) left humerus of Meleagris gallopavo, USNM BIRDS 556334 f, caudal aspect; C) fossil left humerus of Meleagris sp., USNM PAL 641067, caudal aspect; D) fossil right femur of Coragyps atratus, USNM PAL 641790, cranial aspect; E) right femur of C. atratus, USNM BIRDS 647499 m, cranial aspect; F) fossil proximal right carpometacarpus of fossil Branta dickeyi, USNM PAL 641972, ventral aspect; G) proximal right carpometacarpus of B. canadensis, USNM BIRDS 488182 m, ventral aspect; H) left tarsometatarsus of Falcipennis canadensis, USNM BIRDS 557527 f, plantar aspect; I) fossil left tarsometatarsus of Bonasa umbellus, USNM PAL 641979, plantar aspect; J) left tarsometatarsus of B. umbellus, USNM BIRDS 600360 f imm., plantar aspect; K) fossil left tarsometatarsus of Ectopistes migratorius, USNM PAL 769090, plantar aspect; L) tarsometatarsus of E. migratorius, USNM BIRDS 292904 (captive), plantar aspect; M) fossil left femur of Megascops guildayi, USNM PAL 769089, caudal aspect; N) left femur of Megascops asio, USNM 623630 f, caudal aspect; O) fossil right ulna of M. guildayi, USNM PAL 641984, ventral aspect; P) right ulna of M. asio, USNM BIRDS 623630 f, ventral aspect; Q) right tarsometatarsus of Perisoreus canadensis, USNM BIRDS 639077 f, dorsal aspect; R) fossil right tarsometatarsus of a species of jay (Corvidae, aff. Perisoreus/Cyanocitta), CM 24274, dorsal aspect; S) fossil right tarsometatarsus of a species of jay (Corvidae, aff. Cyanocitta/Perisoreus), USNM PAL 641989, dorsal aspect; T) right tarsometatarsus of Cyanocitta cyanea, USNM BIRDS 499504 f, dorsal aspect. Scale bar 1, for images A–G, = 2 cm. Scale bar 2, for images H–N, = 1 cm.