What is "trimerorhachis"

Trimerorhachis is an extinct genus of dvinosaurian temnospondyl within the family Trimerorhachidae. It is known from the Early Permian of the southwestern United States, with most fossil specimens having been found in Texas (its fossils are very common in the north-central part of the state). The type species of Trimerorhachis, T. insignis, was named by American paleontologist Edward Drinker Cope in 1878. Cope named a second species from Texas, T. mesops, in 1896. The species T. rogersi (named in 1955) and T. greggi (named in 2013) are also from Texas, and the species T. sandovalensis (named in 1980) is from New Mexico.