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new reference and some taxonomy
A quite recent interesting paper which has not been mentioned yet:
David Dilkes 1998: The Early Triassic rhynchosaur Mesosuchus browni
and the interrelationships of basal archosauromorph reptiles.
Philosophical Transactions of the Royal Society series B 353,
The author restudies some well preserved remains of the primitive
rhynchosaur Mesosuchus and confirms it to be the most plesiomorphic
member of Rhynchosauria. A historical review of rhynchosaur taxonomy
is given with some additional comments on doubtful rhynchosaur taxa.
The most interesting part of the paper is a new phylogenetic
analysis, including six well-known rhynchosaur taxa, as well as some
early diapsids, prolacertiforms, choristoderes and archosauromorphs.
The technical aspects of this analysis I gladly leave to the more
educated on this list: here are some remarkable conclusions:
The rhynchosaurs form a strongly supported clade (Rhynchosauria is
properly defined as node-based taxon) which forms the sister group of
a clade consisting of Prolacerta and Archosauriformes (represented by
Euparkeria and Proterosuchus in the cladogram). Indeed,
Prolacertiformes is paraphyletic, as Prolacerta shares a more recent
common ancestor with Archosauriformes than with the other taxa that
traditionally have been included in Prolacertiformes (Protorosaurus,
Macrocnemus, Langobardisaurus, Tanystropheus, Megalancosaurus and
Drepanosaurus): these remaining taxa still form a clade that branches
off at the base of Archosauromorpha.
Choristoderes (represented by Champsosaurus, Cteniogenys and
Lazarussuchus) still form a clade (Choristodera is properly defined
as node-based taxon), but not within Archosauromorpha; the clade even
falls outside Sauria (most recent common ancestor of Lepidosauria and
Archosauria plus all descendants).