Labyrinthodont. Crossopterygian. Class Amphibia. Subclass Labyrinthodontia. Class Amphibia ... Evolution of Lobefin Fishes and Amphibians. Class Reptilia. Order ...
Devonian the Age of Fish Dunkelosteus Life on Land First fossils of life on land Ordovician Period Possibly Middle Cambrian Why did Earth go so long without life ...
are evidence of one of the earliest four-legged animals on land. Photo courtesy of Ken Higgs, U. ... and larval stages. The evolutionary pathway to vertebrates ...
(1) Bottom-dwelling filter feeder with lophophore arms (2) ... (Cephalochordate) (Urochordate) (Enteropneusts) Possible evolutionary tree of early vertebrates ...
DIPNOI (lungfishes) Known from later part of Early Devonian to present. ... Lungfish pectoral girdle has complete compliment of paired dermal elements: ...
Gill Arch Hypothesis. Fin Spine Hypothesis. Fin Fold Hypothesis ... whale. Limbs: functional adaptations. 4th digit of hand. Forearm and hand. Forearm and hand ...
See a recovery after the Late Devonian extinction of tabulate ... by the placoderms, the stethacanthids exploded into a riot of bizarre forms and lifestyles. ...