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Fwd: Reproductive phylogeny of maniraptorans
DARLA K. ZELENITSKY, FRANÇOIS THERRIEN (2008)
PHYLOGENETIC ANALYSIS OF REPRODUCTIVE TRAITS OF MANIRAPTORAN THEROPODS
AND ITS IMPLICATIONS FOR EGG PARATAXONOMY
PALAEONTOLOGY
doi:10.1111/j.1475-4983.2008.00770.x
abstract:A phylogenetic analysis of reproductive and oological (egg)
traits of theropod taxa allows determination of the sequence in which
these traits evolved in Theropoda. Our results indicate that several
avian reproductive traits, such as adults sitting on eggs,
asymmetrical eggs, unornamented eggshell surface, and complex eggshell
ultrastructure, were already present in non-avian maniraptorans, and
could have evolved in more basal theropods. In addition, non-avian
maniraptorans laid two eggs at a time and orientated their eggs
subvertically or subhorizontally in their nests, features not retained
by neornithine birds. Based on our cladistic analysis it is also
possible to infer the phylogenetic affinity of ootaxa of unknown
parentage: Protoceratopsidovum was laid by a maniraptoran more derived
than oviraptorids, and Parvoolithus probably belonged to a Cretaceous
bird. Finally, our analysis reveals that many of the high-level
categories of egg parataxonomy (morphotypes and basic types) are
unnatural groupings (i.e. non-monophyletic). We recommend that these
high-level categories be abandoned because oofamilies are sufficient
to categorize egg taxa.
---------- Forwarded message ----------
From: GUY LEAHY <xrciseguy@q.com>
Date: Sun, May 18, 2008 at 1:06 AM
Subject: Reproductive phylogeny of maniraptorans
To: Dinosaur Mailing List <dinosaur@usc.edu>
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