A new fossil Eucrytodiran is recognized as a new species and named Glenrosechelys brooksi. Its presence in the Lower Cretaceous Glen Rose Formation provides the first record of non-chelonioid marine turtles from Texas.

Phylogenetic analyses strongly support a new monophyletic clade within Eurcyptodira, referred to as the Glen Rose clade, that includes ((Angola turtle + Erquelinnesia gosseleti) Eculastes wielandi) Sandownia harrisi) Glenrosechelys brooksi) Solnhofia parsonsi). Synapomorphies uniting the new clade include a character that suggests a duraphagous type feeding behavior, or that food was processed by blunt crushing. Their diet almost certainly consisted of hard-shelled invertebrates like clams and other mollusks. In addition, the group possesses a broad, low skull roof with slight temporal emargination and cheek emargination, and small, somewhat anterodorsally oriented eyes. Glenrosechelys brooksi represents a growth series, maintained a resident population that inhabited a shallow sea during the Early Cretaceous of Texas, and were non-migratory.

This study indicates three separate invasion of the sea by turtles when using cranial and post cranial characters. This is the first analysis that unites Euclastes wielandi with non-cheloniid marine turtles. Geographic and temporal distribution shows that members representing the Glen Rose clade first appear in the Late Jurassic in the northern hemisphere, but diversity greatly increased by the Middle Miocene of the Cenozoic.