Both species have similar body morphology, in that both resembled tadpoles with forked tails. Scale morphology differs in that A. bifurcata has forked scales with two prong-like spires,[1] and that A. turbinata has bulbous, pointed scales that resemble upside-down spinning tops.[3]
References
^ abMärss, Tiiu, VH Wilson, Mark, & Thorsteinsson, Raymond. "New thelodont (Agnatha) and possible chondrichthyan (Gnathostomata) taxa established in the Silurian and Lower Devonian of the Canadian Arctic Archipelago."Proceedings of the Estonian Academy of Sciences, Geology. Vol. 51. No. 2. Estonian Academy Publishers, 2002.
^Wilson, Mark VH, and Tiiu Märss. "Thelodont phylogeny revisited, with inclusion of key scale-based taxa." Estonian Journal of Earth Sciences 58.4 (2009): 297œ310. [1]
^ abSoehn, K. L., Märss, T., Caldwell, M. W. & Wilson, M. V. H., 2001: New and biostratigraphically useful thelodonts from the Silurian of the Mackenzie Mountains, Northwest Territories, Canada. Journal of Vertebrate Paleontology, 21: 651-659 [2]