Plethodon ainsworthi

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The division of living beings into systematics is a continuous subject of research. Different systematic classifications exist side by side and one after the other. The taxon treated here has become obsolete due to new research or is not part of the group systematics presented in the German-language Wikipedia.

Plethodon ainsworthi is a now invalid species of salamander from the genus of the forest salamander ( Plethodon ). It is named after Jackson Harold Ainsworth, who collected the only two known specimens in June 1964.

features

Plethodon ainsworthi has been described as a slender forest salamander. He had four toes on his forelegs and five on his hind limbs. The tail was cylindrical in cross section and had no basal (close to the body) narrowing. The head width was included 7.9 to 8.4 times the head-torso length . The limbs were short. There were four to six rib folds between the adjacent limbs. The overall body color was dark black-brown with no discernible pattern.

The holotype measures 47.5 mm from the snout to the front edge of the trunk and 51.5 mm to the rear edge of the trunk. The specimen is very brittle, apparently due to the strong formalin in which it was placed. The left fore limb, the distal part of the tail, all toes on both hind limbs, and the first toe on the right fore limb have broken off. The specimen was fixed with an open mouth. When trying to open the mouth further, the connection seam was severely damaged. By measuring the existing limbs and generously estimating the length of the toes, the first describer James Lazell came to the conclusion that there were at least four rib folds between the attached limbs in this specimen. There are 16 side furrows on each side. The peritoneum is light gray-brown, just like the other exposed muscles. There are 40 teeth in the rows of the upper jaw and the intermediate jaw. The palatal teeth form a large central field, 12 teeth wide and 18 teeth long. There are two separate, arched rows of teeth on the ploughshare leg , each with 8 to 10 teeth.

The paratype was largely destroyed during the examination of the vertebral bones . Before this failed attempt, however, the specimen could be photographed and morphologically analyzed. Apparently the bones were completely decalcified by the long soaking in the strong formalin. The paratype measured 52 mm from the snout to the front edge of the trunk and 57 mm to the rear edge of the trunk. On initial examination, all four limbs were intact and there were five rib folds on the right side and six on the left. Upon further examination, both forelimbs and the toes of both hind limbs were lost. There are 16 side furrows on either side, with one Y-shaped furrow in the rib counting as two furrows. The peritoneum is not clearly pigmented. The texture of the teeth is exactly like the holotype.

Occurrence and habitat

Ainsworth collected the two specimens near Bay Springs, Jasper County , Mississippi . The habitat consists of mixed, moderately arid woodland with numerous springs and seepage that generally drains north and east into Tallahoma Creek.

Status and system

Despite multiple searches between 1991 and 1995 as well as in 1997, the species could not be rediscovered. In 2004 the species was declared extinct by the IUCN. In 2013 it was shown on the basis of a study that Plethodon ainsworthi does not represent a valid species, but that it is poorly preserved specimens of Plethodon mississippi .

literature

  • James Lazell: New Salamander of the Genus Plethodon from Mississippi . In: Copeia . Vol. 1998, No. 4, 1998, pp. 967-970 ( Jstor , accessed March 24, 2013).

Web links

Individual evidence

  1. ^ John G. Himes, David C. Beckett: The Status of Plethodon ainsworthi Lazell: Extinct, Extant, or Nonexistent? Southeastern Naturalist 12 (4), 2013, pp. 851-856.