They diverged from Diplodocidae in the Mid-Jurassic , as evidenced by the diversity of dicraeosaurids in both South America and East Africa when Gondwana was still united by land .
The clade is monophyletic and well - supported phylogenetically with thirteen unambiguous synapomorphies uniting it .
synapomorphies diverged from Diplodocidae in the Mid-Jurassic , as evidenced by the diversity of dicraeosaurids in both South America and East Africa when Gondwana was still united by land .
The clade is monophyletic and well - supported phylogenetically with thirteen unambiguous synapomorphies uniting it .