▁of ▁the ▁first ▁Car bon ifer ous ▁t et rap ods . ▁They ▁were ▁first ▁described ▁in ▁ 1 8 6 2 ▁and ▁further ▁described ▁in ▁ 1 8 7 0 ▁when ▁two ▁more ▁c ran iums ▁were ▁found . ▁It ▁is ▁mostly ▁associated ▁with ▁the ▁area ▁of ▁the ▁United ▁Kingdom . ▁They ▁share ▁features ▁with ▁modern ▁re pt iles ▁as ▁well ▁as ▁with ▁fish . ▁They ▁had ▁ 4 ▁p addle - like ▁lim bs ▁that ▁they ▁used ▁to ▁sw im ▁in ▁la kes , ▁but ▁they ▁bre athed ▁air . ▁Their ▁di et ▁consisted ▁mostly ▁of ▁live ▁fish . ▁They ▁are ▁of ▁the ▁order ▁B ap het idae ▁which ▁are ▁distinguished ▁by ▁their ▁key hole ▁sh aped ▁or bits , ▁while ▁L ox om ma ▁themselves ▁are ▁distinguished ▁by ▁the ▁unique ▁texture ▁on ▁their ▁sk ull s , ▁said ▁to ▁be ▁h oney comb - like . ▁ ▁History ▁and ▁discovery ▁▁ ▁The ▁genus ▁L ox om ma ▁was ▁discovered ▁and ▁named ▁by ▁Thomas ▁Henry ▁H ux ley ▁in ▁ 1 8 6 2 ▁via ▁a ▁near ▁perfect ▁c ran ium , ▁a ▁verte bra ▁and ▁a ▁rib ▁in ▁the ▁Lan ark shire ▁coal - field ▁of ▁Scotland . ▁ ▁The ▁family ▁B ap het idae ▁were ▁among ▁the ▁first ▁Car bon ifer ous ▁t et rap ods ▁to ▁be ▁found ▁and ▁were ▁first ▁described ▁by ▁William ▁Daw son ▁in ▁ 1 8 6 3 , ▁with ▁L ox om ma ▁being ▁the ▁earliest ▁in ▁the ▁family . ▁The ▁sub family