Class Mammalia
Order Artiodactyla
Suborder Tylopoda
Family Camelidae
Hemiauchenia sp.—American Llamas // Hemiauchenia blancoensis—Blanco Llama // Hemiauchenia gracilis—Gracile Llama // Hemiauchenia macrocephala—Big-headed Llama
Synonyms. Tanupolama
The llamas are relatively long-limbed camels built quite differently than the stocky Camelops.
Several sites have fossils of Hemiauchenia preserved, but the publications do not list a species identification.
Sites.
Late Blancan: Curtis Ranch (Lindsay 1984).
Irvingtonian: El Paso (UTEP: cf.)
Late Rancholabrean: East Cave (O'Laughlin 1977).
Early/Early-Mid Wisconsin: Sabertooth Camel Maze (Harris 1993c).
Late Wisconsin: Bison Chamber (Harris 1993c); Human Corridor (Harris 1993c).
Late Wisconsin/Holocene: Conkling Cavern (Conkling 1932).
Fig. 1 shows the typical proportions of the fused metatarsals III and IV.
Fig. 1. Posterior view of the fused metatarsals III and IV of Hemiauchenia macrocephala. White bar is 10 cm (3.94 in) long.
Literature.
Conkling 1932; Harris 1993c; Morgan and Lucas 2003; O'Laughlin 1977; Lindsay 1984.
This is a moderately large Hemiauchenia and is the most common member of the genus recovered from Blancan sites in New Mexico (Morgan et al. 2011).
Sites.
Late Blancan: Caballo (Morgan et al. 2011); San Simon Fauna (Morgan and White 2005); Virden (Morgan et al. 2008).
Literature.
Morgan and White 2005; Morgan et al. 2008; Morgan et al. 2011.
Meachen (2005) described a relatively small, gracile Hemiauchenia from several sites in Florida, mentioning that a phalanx possibly pertaining to this taxon was present in the Blancan of southeastern Arizona. Morgan et al. (2011) noted its presence at Virden and La Union and characterized its size as smaller than H. macrocephala.
Sites.
Latest Blancan: La Union (Morgan et al. 2011); Virden (Morgan et al. 2011).
Literature.
Meachen 2005; Morgan et al. 2011.
Synonyms. Tanupolama stevensi.
Hemiauchenia macrocephala appears to be the only post-Blancan species of the genus in our region. Likely those in the Hemiauchenia sp. account also belong to this species. Isolated post-cranial material (frequently consisting of phalanges) seem to be separable from that of Camelops by size alone.
This is a large animal, very roughly the same size as Camelops hesternus which had limbs about 20% longer than those of the living Dromedary Camel (Kurtén and Anderson 1980). However, where Camelops limb bones are relatively short stocky, those of Hemiauchenia are extraordinarily slender and long (see Fig. 1 of the Hemiauchenia sp. account).
A number of elements of at least three adults and one young individual were recovered from the Camel Room site of Dry Cave. The position of the skeletal elements suggests that a small herd (family group?) fell together into the Entrance Fissure of Dry Cave. The physical layout of the cave entrance makes this more likely than it might seem, especially if the group was fleeing from a predator. With an approach from the downslope side, the entrance is not apparent until a few feet from the drop off.
Two of the three adult mandibles lack any indication of p3, which might suggest a familial genetic trait. Webb (1974) mentions that the type specimen of the species lacks this tooth, but that it occurs in the greater portion of the H. macrocephala samples.
Fig. 1. Lateral view of the maxilla of Hemiauchenia macrocephala from the Camel Room site, Dry Cave. Anterior is to the right. The crescent-shaped portion to the upper left is part of the zygomatic arch. Scale in mm.
Fig. 1. Palatal view of the same specimen as in Fig. 1. P3, P4, and the three molars show nicely. Scale in mm.
Fig. 3. Phalanges of Hemiauchenia macrocephala from Camel Room site, Dry Cave. Left upper, PH III, oblique dorsal view; left lower, PH II, ventral view; right, PH I, ventral view. Scale in mm.
Sites.
Irvingtonian: Gutierrez Gravel Pit (Morgan and Lucas 2005); Tijeras Arroyo (Morgan and Lucas 2005).
Rancholabrean: Jal (Morgan and Lucas 2005); Roswell (Morgan and Lucas 2005).
Early Rancholabrean: Albuquerque Gravel Pits (Morgan and Lucas 2005).
Wisconsin: Big Manhole Cave (Harris 1993c).
Mid Wisconsin: Pendejo Cave (Harris 2003).
Mid/Late Wisconsin/Holocene: Sierra Diablo Cave (UTEP).
Late Wisconsin: Algerita Blossom Cave (Harris 1993c); Animal Fair 18-20 ka (Harris 1989); Blackwater Loc. No. 1 (Morgan and Lucas 2005); Camel Room (Harris 1993c); Charlies Parlor (Harris 1989); Pendejo Cave (Harris 2003); Sandia Cave (Thompson and Morgan 2001); TT II (Harris 1993c).
Late Wisconsin/Holocene: Isleta Cave No. 2 (Harris 1993c); Pendejo Cave (Harris 2003).
Literature.
Harris 1989, 1993c, 2003; Kurtén and Anderson 1980; Morgan and Lucas 2005; Thompson and Morgan 2001; Webb 1974.
Last Update: 17 Mar 2013