|Basic info||Taxonomic history||Classification||Relationships|
|Morphology||Ecology and taphonomy||External Literature Search||Age range and collections|
Mammalia - Ungulata - Camelidae
If no rank is listed, the taxon is considered an unranked clade in modern classifications. Ranks may be repeated or presented in the wrong order because authors working on different parts of the classification may disagree about how to rank taxa.
|S. D. Webb and J. A. Meachen 2004||The long narrow rostrum extends 32 mm ahead of I3 and is widest across C1. The en- larged braincase has a low sagittal crest. The zy- gomatic arch is deep and sigmoid, not shallow and straight. The posterior narial opening is broadly rounded and opens opposite M2. The bullae are thick and rectangular in outline. The paroccipital process extends well below the bulla and gives or- igin to a well developed M. digastricus. The upper and lower diastemata (posterior to first premolars) are moderately long (30–35 mm long.) The dental formula is I1, C1, P4–3, M3, and I3, C1, P4–3, M3. P1 and P1 are single rooted; P2 and P2 are reduced or absent. P3 and P3 are nearly as long as P4 and P4 respectively. The lingual crescent of P3 is nearly complete. The strong ‘‘llama buttresses’’ on the lower molars reach maximum expression in Stage 3 wear. The molars are weakly to moderately hyp- sodont. The metapodials are very long and slender.
Pleiolama differs from Hemiauchenia in its smaller size, shorter diastema, P1/1 and P3/3 larger, lower incisors more delicate, and symphysis nar- rower. Pleiolama differs from Palaeolama in its larger P3/3, simpler P4, and much longer metapodi- als.
Pleiolama also differs from Alforjas in P1/1 and P3/3 larger, lower incisors more delicate, symphysis narrower, cheek teeth much less hypsodont, palatine notch rounded and opposite M2, and metapodials longer. This new genus can be distinguished from Camelops in most of the same features as from Al- forjas, but in addition, it retains P1/1 and P2/2.