EUSAUROPTERYGIA

Classification

Sauropterygia > Eosauropterygia> Eusauropterygia

Discussion

The clade Eusauropterygia includes the Eosauropterygia minus the superfamily Pachypleurosauria.The genus Corosaurus was originally placed outside of Eosauropterygia but is now recognised as a Pistosauroid (Rieppel, 1998). The Eusauropterygia are defined by a selection of derived characters including (Rieppel 1997, Sues 1986)

• Elongation of the jaws and mandibular symphysis (large skull)
• Strongly procumbent rostral dentition and paired maxillary fangs
• 5 premaxillary teeth
• Small orbit (relative to skull length)
• Dorsoventral depression of the skull

• Relative size increase in the upper temporal fenestrae
• Complex dual jaw adductor system
• Scapular proportionately small.
• Five or six sacral vertebrae.