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Class Aves
Order Passeriformes
Family Icteridae


Pyelorhamphus molothroides A. H. Miller 1932—Thick-billed CowbirdPleistocene regional distribution of Pyelorhamphus molothroides.

Miller (1932) described a new genus and species of cowbird from Shelter Cave. His description is as follows (1932:339-40):

Pyelorhamphus new genus.

   Generic characters.—Lower mandible most nearly like Molothrus and Tangavius in the deep, short, sharply pointed bill, but groove for tongue relatively much deeper and narrower; tomial contour, viewed dorsally, strongly concave; tomium, viewed laterally, straight in distal portion (extreme tip lacking) but strongly, although not abruptly, convex basally with ramus relatively deep in this region; ramus posterior to termination of horn sheath strongly deflected downward; angle of rami at symphysis relatively obtuse indicating broad or massive head relative to length of bill.
   Type.—Pyelorhamphus molothroides.

Pyelorhamphus molothroides new species.

   Type.—Lower mandible, lacking the extreme tip and most of the rami posterior to the region of the horn sheath, no. 320, locality 1010, Los Angeles Museum, from Quaternary of Shelter Cave, west slope of Organ Mountains, Doña Ana County, New Mexico. Collected by H. A. Wylde and W. M. Strong, August 25, 1930. (See Plate IV, figs. 1, 2 and 3.)

Miller (p. 40) characterized the upper mandible as: "Culmen nearly straight anterior to nostrils; culmen moderately curved above posterior part of nostrils; internarial bridge much broader anteriorly than posteriorly; base of culmen (nasal process of maxilla) elevated posteriorly into distinct ridge rising above posterior part of nasal fossae; angle formed by junction of anterior and ventral margins of nostrils only slightly greater than 90°; maxillo-palatine groove deep and divided medially into two parts; grooves for tomium of lower mandible strongly divergent posteriorly, corresponding in shape with tomium of lower mandible no. 320."

Measurements of the holotype and referred upper mandible are (p. 20):

  Lower mandible: greatest depth of ramus, near base of tomium, 4.6 mm.; greatest width across rami immediately proximad of base of horn sheath, 11.2 mm.; distance from symphysis to proximal end of tomium (base of horn sheath), 7.0 mm.; depth of groove at symphysis, 3.3 mm
Upper mandible: greatest anteroposterior diameter of nostril, 5.2 mm.; greatest depth perpendicular to tomium at point of attachment to jugals, 4.6 mm.

Sites. Mid Wisconsin-Holocene: Shelter Cave (A. H. Miller 1932).

Literature. A. H. Miller 1932.


Last Update: 29 Sep 2008