Plestiodon is a
genus of
lizards in the
familyScincidae (skinks). The genus contains many
species formerly classified under the genus Eumeces, except those now placed in Mesoscincus. They are secretive, agile animals with a cylindrical body covered with smooth, shiny scales. They are distributed from
East Asia to throughout
North America from southern
Canada south to
Mexico, including oceanic islands such as
Bermuda.
Defensive mechanism
The conspicuous coloring of species of Plestiodon is a survival trait: it attracts a predator's attention to the tail of the animal, which will break off when grabbed. A skink thus often manages to escape and hide under some rock, log, or fallen leaves while the predator still contemplates the wildly thrashing severed tail. (This is an instance of what is called
autotomy: voluntarily shedding a body part in order to escape, and later re generating the body part.) After the tail regenerates, it usually has the same color as the rest of the body and is typically shorter than the original tail. In some species, regrown tails are pinkish. A regrown tail has a
cartilaginous rod for support instead of
vertebrae.
Reproduction
Plestiodon are all[citation needed]oviparous. The female lays eggs once a year after the breeding season in spring. The
clutch size varies and is typically around 5 to 10 eggs. The hatchlings appear in late summer.
Like other
reptiles, Plestiodon skinks are "cold-blooded" — they are
ectothermic animals: their
metabolism cannot regulate their
body temperature. To warm up, they often bask in the sun. In colder climates, they
hibernate in winter in burrows below the
frost line. In hot climates, they are active mainly in the morning and evening, staying under cover during the hottest hours of the day to avoid overheating.
Systematics
Recently two
taxonomic revisions have been made regarding the 19th century
genusEumeces. They both resulted in similar results; the
genus is
paraphyletic and must be "sliced up" into several different
genera. Griffith et al. (2000) proposed that the
type species for Eumeces, E. pavimentatus, which is considered by many to be a
subspecies of Eumeces schneiderii, should be changed to Lacerta fasciata, so that the genus name Eumeces would stay with the most species-rich
clade. However this petition has not been verified by the
International Commission on Zoological Nomenclature.
Schmitz et al. argued that Griffith et al. violated the Code and rejected the proposal on good grounds. Thus only the African
species of the Eumeces schneiderii group still belong to the genus Eumeces.
Austin JJ,
Arnold EN (2006). "Using ancient and recent DNA to explore relationships of extinct and endangered Leiolopisma skinks (Reptilia: Scincidae) in the Mascarene islands". Molecular Phylogenetics and Evolution39 (2): 503–511.
doi:
10.1016/j.ympev.2005.12.011 (HTML abstract).
Griffith H,
Ngo A,
Murphy RW (2000). "A cladistic evaluation of the cosmopolitan genus Eumeces Wiegmann (Reptilia, Squamata, Scincidae)". Russian Journal of Herpetology7 (1): 1–16.
[1]
Smith HM (2005). "Plestiodon: a Replacement Name for Most Members of the Genus Eumeces in North America". Journal of Kansas Herpetology (14): 15–16.
[4]
Brandley MC,
Schmitz A,
Reeder TW (2005). "Partitioned Bayesian analyses, partition choice, and the phylogenetic relationships of Scincid lizards". Systematic Biology54 (3): 373–390.
[5]
Okamoto, Taku;
Motokawa, Junko;
Toda, Mamoru;
Hikida, Tsutomu (2006). "Parapatric distribution of the lizards, Plestiodon (formerly Eumeces) latiscutatus and P. japonicus (Reptilia: Scincidae) around the Izu Peninsula, central Japan, and its biogeographic implications". Zoological Science23: 419–425.
Motokawa, Junko; Hikida, Tsutomu (2003). "Genetic variation and differentiation in the Japanese five-lined skink, Eumeces latiscutatus (Reptile: Squamata)". Zoological Science20: 97–106.
External links
Wikimedia Commons has media related to Plestiodon.