Ainsworth's salamander

Plethodon ainsworthi is an extinct after knowledge of the IUCN species of salamander of the genus forest salamander ( Plethodon ). It is named after Harold Jackson Ainsworth, who had collected the only two known copies in June 1964.

Features

Plethodon ainsworthi was a slender woodland salamander. He had four toes on the forelimbs and five on the hind limbs. The tail was cylindrical in cross section and had no basal ( proximal ) constriction. The head width contained 7.9 to 8.4 times in head-body length. The limbs were short. There were four to six ribs folds between adjacent limbs. The body coloration was generally dark black brown with no obvious pattern.

The holotype measures 47.5 mm from the snout to the anterior edge of fuselage and 51.5 mm to the rear fuselage edge. The specimen is very fragile, apparently due to the strong formalin, in which it was inserted. The left forelimb, the distal part of the tail, all the toes on both hind limbs and the first toe on the right forelimb are canceled. The specimen was fixed with its mouth open. During the subsequent trial, the mouth to open wider, the seam was badly damaged. By measuring the existing limbs and the generous estimate of the toe length, the first to describe James Lazell came to the conclusion that in this specimen at least four ribs wrinkles between the applied limbs were present. There are 16 side grooves on each side. The peritoneum is pale gray-brown, just like the other exposed muscles. In the ranks of the maxilla and premaxilla are 40 teeth. The palatal teeth form a great midfield, 12 teeth 18 teeth wide and long. There are two separate arcuate rows of teeth on the vomer, each with 8-10 teeth.

The parameter type was largely destroyed during the examination of the vertebral bones. However, before this failed attempt the specimen was photographed and analyzed morphologically. Apparently, the bones were completely decalcified by the long insertion in strong formalin. The para-type mass 52 mm from the snout to the anterior edge of the hull and 57 mm to the rear fuselage edge. In the first study, all four limbs were intact and there was a whole five ribs folds on the right side and six on the left. Upon further inspection of both front limbs, and the toes of both hind limbs were lost. 16, there are side grooves on both sides, wherein a Y-shaped groove in the rib grooves than two is counted. The peritoneum is not much pigmented. The condition of the teeth is just like the holotype.

Occurrence and habitat

Ainsworth collected two specimens near Bay Springs, Jasper County, Mississippi. The habitat includes mixed, moderately dry woodland with numerous springs and seeps, which flow generally north and east in the Tallahoma Creek.

Status

Despite repeated searches in the years 1991 to 1995 and in 1997 could no longer be re-discovered the species. Deforestation, soil erosion and drying up of the sources are apparently the main causes of the disappearance of Plethodon ainsworthi. 2004, the type of the IUCN was declared extinct.