Whatcheeria
Whatcheeria is an extinct genus of early tetrapod from the Early Carboniferous of Iowa. Fossils have been found in 340 million year old fissure fill deposits in the town of Delta. The type species W. deltae was named in 1995. It is classified within the family Whatcheeriidae along with the closely related Pederpes.
Description
Whatcheeria possesses a mixture of both primitive and derived traits. It shares with earlier stem tetrapods a series of lateral lines across the skull, rows of teeth on the palate, and small Meckelian foramina across the surface of the lower jaw. It has a cleithrum, a bone in the pectoral girdle that extends from the scapula. The cleithrum once attached to the skull in lobe-finned fish, the ancestors of tetrapods, but detached to allow the neck to move freely.[1]
Whatcheeria grew to about 1 metre (3.3 ft) long. The skull is deep and the snout is pointed. A hole on the top of the skull behind the eyes called the parietal foramen is relatively large in Whatcheeria. The bones on the skull surface are unusually smooth, unlike the pitted skulls of many other early tetrapods. In front of the eye socket, the prefrontal bone forms a prominent ridge. The prefrontal also projects downward to cover a possible sinus.[1]
History
The type species of Whatcheeria, W. deltae, was named in 1995. Whatcheeria is named after What Cheer, Iowa, the hometown of the man who discovered the first skeletons of the animal. The species is named after Delta, Iowa, the location where the fossils were uncovered. Hundreds of tetrapod fossils were found in the locality, and the majority of these specimens are thought to belong to Whatcheeria. Fish and plant fossils have also been found in the same deposits. Several other tetrapods, including temnospondyls and embolomeres, are known from the Delta locality.[1]
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