Palaeos		Glires
Vertebrates		Lagomorpha

Glires: Lagomorpha

EUARCHONTOGLIRES
|--ARCHONTA
|
`--ANAGALIDA
   |--Anagaloidea
   |  |--Anagalidae
   |  `--Pseudictopidae
   `--Glires
      |--Lagomorpha
      `--RODENTIA

Taxa on This Page

1. Lagomorpha

Descriptions

Lagomorpha : rabbits & pikas. 

Range: from the Eocene? 

Phylogeny: Glires: Rodentia + *. 

Characters: Dental formula 2/1, 0/0, 3/2, 2-3/3. I2/1, with 2nd incisor immediately behind 1st, small and peg-like; incisors ever-growing, with at least some enamel on posterior, as well as anterior, face; flaps of skin can meet behind incisors (can gnaw with mouth closed); C0/0 with large diastema; cheek teeth hypsodont, rootless (in R forms), with transverse ridges; lower cheek teeth laterally closer than uppers, so that only one side occludes at a time and lateral grinding is required; masseter and pterygoideus large; coronoid process and temporalis reduced; fenestrated skull bones, i.e. with areas of thin, lattice-like bone (esp. maxilla & parietals -- see leporidae.jpg); auditory bulla from ectotympanic only & entotympanic is absent; tail reduced or absent; elbow joint limits forelimbs to antero-posterior motion; tibia & fibula distally fused; digits 5/4-5; soles of hind feet generally furred; stance digitigrade when moving quickly; all herbivorous, with very large cecum; various specializations for rapid reproduction including induced ovulation (eggs shed in response to copulation) and 'postpartum estrus' (can conceive immediately after giving birth). 

Note: There are some peculiar parallels between lagomorphs and protoavian dinosaurs, e.g. fenestrated bone, forelimb motion; distal limb fusion, & possibly others. ATW

Comments: The Lagomorpha contains the modern pikas (Ochotona) together with the rabbits and hares (Leporidae). Living lagomorphs practice coprophagy, producing soft faecal pellets that they then re-ingest in order to extract more nutriments from their food (the final digestive wastes are produced as hard pellets that are not re-ingested). - CKT120117

Image: Oryctolagus cuniculus © 1999 by BioImages, used by permission.  

Links: Order Lagomorpha; Rabbit, Hare, and Pika Skulls from Skulls Unlimited ; Kazimir Majorinc Pika Page; Order Lagomorpha; Lagomorpha; Mammalia: Rodentia und Lagomorpha; Entrez-PubMed (abstract); Order Lagomorphia; Lagomorphs; Untitled Document; Leaping Lepus - The Hall of Florida Fossils; Oklahoma Museum of Natural History; LITERATURA DE LAGOMORFOS EN CHILE DESDE 1847; Order LAGOMORPHA; Lagomorphs - EnchantedLearning.com; Order Lagomorpha; ???? (CSIS); Lagomorpha.  ATW030406.