Varanosaurus greenleeorum (V. acitirostris Broili 1904; Early Permian, 275 mya). Benson 2012 considered Varanosaurus as a late surviving member of the Ophiacodontia following Berman et al. (1995), but these two specimens are basal to Ophiacodon in the LRT. The long rostrum and short cranial region of Varanosaurus is shared with Ophiacodon. The skull is low and teeth are side-by-side.

Berman et al. (1995) reported on the holotype BSPHM 1901 XV 20 (above) and FMNH PR 1760 (below).

Dendromaia unamakiensis (the small specimen, Maddin, Mann and Hebert 2020; Late Carboniferous) was originally considered a juvenile found beneath the femur of a conspecific adult. Here the two are unrelated roommates. The large specimen nests among skull-only taxa like Acleistorhinus and Delorhynchus. The small specimen nests here between the two Varanosaurus specimens.

Benson RBJ 2012. Interrelationships of basal synapsids: cranial and postcranial morphological partitions suggest different topologies. Journal of Systematic Palaeontology, iFirst 2012, 1-24.

Berman D S, Reisz RR, Bolt JR, and Scott D. 1995. The cranial anatomy and relationships of the synapsid Varanosaurus (Eupelycosauria: Ophiacodontidae) from the Early Permian of Texas and Oklahoma. Annals of Carnegie Museum 64: 99-133.

Broili F 1904. Permische Stegocephalen und Reptilien aus Texas. Palaeontographica 51:1-120.

Maddin HC, Mann A and Hebert B 2020. Varanopid from the Carboniferous of Nova Scotia reveals evidence of parental care in amniotes. Nature ecology & evolution 4:50–56.

Romer AS and Price LW1940. Review of the Pelycosauria. Geological Society of America Special Papers 28: 1-538.

wiki/Varanosaurus
wiki/Dendromaia