Data from: Body size evolution in Titanosauriformes (Sauropoda, Macronaria)

Titanosauriformes is a conspicuous and diverse group of sauropod dinosaurs
that inhabited almost all land masses during Cretaceous times. Besides the
diversity of forms, the clade comprises one of the largest land animals
found so far, Argentinosaurus, as well as some of the smallest sauropods
known to date, Europasaurus and Magyarosaurus. They are therefore good
candidates for studies on body size trends such as the Cope's rule,
the tendency towards an increase in body size in an evolutionary lineage.
We used statistical methods to assess body size changes under both
phylogenetic and nonphylogenetic approaches to identify body size trends
in Titanosauriformes. Femoral lengths were collected (or estimated from
humeral length) from 46 titanosauriform species and used as a proxy for
body size. Our findings show that there is no increase or decrease in
titanosauriform body size with age along the Cretaceous and that negative
changes in body size are more common than positive ones (although not
statistically significant) for most of the titanosauriform subclades (e.g.
Saltasaridae, Lithostrotia, Titanosauria and Somphospondyli). Therefore,
Cope's rule is not supported in titanosauriform evolution. Finally,
we also found a trend towards a decrease of titanosauriform mean body size
coupled with an increase in body size standard deviation, both supporting
an increase in body size variation towards the end of Cretaceous.