`` Pogonodon '' was described in 1880 by Edward Drinker Cope . Two species are recognized , `` P. davisi '' and `` P. platycopis '' . `` Pogonodon '' was described in 1880 by Edward Drinker Cope , two species are known : `` P. davisi '' and `` P. platycopis '' . Pogonodon was recognised by Edward Drinker Cope in 1880 , two species are described : `` P. davisi '' and `` P. platycopis '' .