Plestiodon

Taxobox

---

image_width = 240px
image_caption = "Plestiodon fasciatus"
regnum = Animalia
phylum = Chordata
classis = Reptilia
ordo = Squamata
infraordo = Scincomorpha
familia = Scincidae
genus = "Plestiodon"
genus_authority =
subdivision_ranks =
subdivision =

"Plestiodon" is the name for genus of American lizards formerly referred to as "Eumeces", except those now placed in "Mesoscincus".

The genus "Plestiodon" are skinks (family Scincidae). They are secretive, agile animals with a cylindrical body covered with smooth, shiny scales.

Ecology

The conspicuous coloring 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.)

The skink regrows an autotomized tail, which then usually has the same color as the rest of the body and typically is also shorter than the original tail. In some species, regrown tails are pinkish. A regrown tail has a cartilaginous rod for support instead of vertebrae.

"Eumeces" are all 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, these 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.

These skinks are not dangerous to humans. They are not especially aggressive, but will bite if provoked. The bite is not very painful, even to children, who may find great amusement with the spectacle of a lizard dangling from their forefinger. Whether the skink finds this experience amusing as well is doubtful. "Eumeces" are delicate animals whose tail breaks off easily, and herpetologists and other enthusiasts should handle them with great care, if at all.

Systematics

Two Taxonomic revisions have been mabe in the 19th centure regarding genus Eumeces. They both resuled in similar results; the genus is paraphyletic and must be sliced up into several different genus. Griffith et al. (2000) proposed that the type species for " Eumeces E. pavimentatus", which is considered by many to be a subspecies of "Eumeces schneideri", 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. Schimtz et al. argued that Griffith et al. violated the Code and rejected the proposal on good grounds. Thus only the African species of "Eumeces schneideri"-group belong to the genus Eumeces.

Within "Eumeces" the following species are recognized:
*"Eumeces algeriensis"
*"Eumeces blythianus"
*"Eumeces schneideri"

Some species that were formerly considered "Eumeces" have now been assigned to new genera:

Now in "Plestiodon"
*"Plestiodon anthracinus", Coal Skink
*"Plestiodon barbouri", Barbour's Skink (Japan)
*"Plestiodon brevirostris", Short-nose Skink (Mexico)
*"Plestiodon callicephalus", North American Mountain Skink
*"Plestiodon capito"
*"Plestiodon chinensis", Chinese Skink (East Asia: China, Korea, Japan)
*"Plestiodon colimensis" (Mexico)
*"Plestiodon copei" (Mexico)
*"Plestiodon coreensis", Korean Skink (Korea)
*"Plestiodon dugesii" (Mexico) - rare
*"Plestiodon egregius", Mole Skink
*"Plestiodon elegans", Five-striped Blue-tailed Skink or Shanghai Skink (East Asia)
*"Plestiodon fasciatus", Common Five-lined Skink
*"Plestiodon gilberti", Gilbert's Skink (North America)
*"Plestiodon inexpectatus", Southeastern Five-lined Skink
*"Plestiodon kishinouyei", Kishinoue's Giant Skink
*"Plestiodon lagunensis", San Lucan Skink
*"Plestiodon laticeps", Broad-headed Skink
*"Plestiodon latiscutatus", Japanese Skink (Japan)
*"Plestiodon liui" (Asia)
*"Plestiodon longirostris", Bermuda Rock Skink
*"Plestiodon lynxe", Oak Forest Skink (Mexico)
*"Plestiodon marginatus", Ryūkyū Five-lined Skink (Okinawa and Amami Islands)
*"Plestiodon multilineatus"
*"Plestiodon multivirgatus", Many-lined Skink
** "Plestiodon (multivirgatus) gaigeae", Variable Skink (North America) - sometimes "Eumeces (multivirgatus) epipleurotus"
*"Plestiodon obsoletus", Great Plains Skink
*"Plestiodon ochoterenae"
*"Plestiodon okadae", Okada's Five-lined Skink (Japan)
*"Plestiodon parviauriculatus", Northern Pygmy Skink (Mexico)
*"Plestiodon parvulus", Southern Pygmy Skink (Mexico)
*"Plestiodon popei" (Asia)
*"Plestiodon quadrilineatus", Four-lined Asian Skink
*"Plestiodon septentrionalis", Prairie Skink - includes "Eumeces obtusirostris"
*"Plestiodon skiltonianus", Western Skink
*"Plestiodon stimpsonii", Yaeyama Seven-lined Skink (Japan)
*"Plestiodon sumichrasti" (Mexico)
*"Plestiodon tamdaoensis"
*"Plestiodon tetragrammus", Four-lined Skink
*"Plestiodon tunganus"

Now in "Eurylepis":
*"Eumeces indothalensis" - now "Eurylepis indothalensis"
*"Eumeces poonaensis" - now "Eurylepis poonaensis"
*"Eumeces taeniolatus" - now "Eurylepis taeniolatus"

Now in "Mesoscincus":
*"Eumeces altamirani" - now "Mesoscincus altamirani"
*"Eumeces managuae" - now "Mesoscincus managuae"
*"Eumeces schwartzei" - now "Mesoscincus schwartzei"

References

* (2006): Using ancient and recent DNA to explore relationships of extinct and endangered "Leiolopisma" skinks (Reptilia: Scincidae) in the Mascarene islands. "Molecular Phylogenetics and Evolution" 39(2): 503–511. doi|10.1016/j.ympev.2005.12.011 (HTML abstract)

* Griffith, H., A. Ngo & R. W. Murphy 2000 A cladistic evaluation of the cosmopolitan genus Eumeces Wiegmann (Reptilia, Squamata, Scincidae). Russ. J. Herpetol. 7 (1): 1-16 [http://www.cnah.org/pdf_files/245.pdf]

* Schmitz, Andreas; Patrick Mausfeld and Dirk Embert. 2004. Molecular studies on the genus Eumeces Wiegmann, 1834: phylogenetic relationships and taxonomic implications. Hamadryad 28 (1-2): 73 – 89 [http://www.naherpetology.org/pdf_files/191.pdf] [http://www.cnah.org/pdf_files/191.pdf]

* Smith Hobart M. 2005. Plestiodon: a Replacement Name for Most Members of the Genus Eumeces in North America. Journal of Kansas Herpetology. Number 14. [http://www.cnah.org/khs/JKH_14.pdf#page=17]

* Brandley M.C. Schmitz A. Reeder T.W. 2005. Partitioned Bayesian analyses, partition choice, and the phylogenetic relationships of Scincid lizards. Systematic Biology. 54(3): pp. 373-390) [http://socrates.berkeley.edu/~brandley/pubs/Brandley_et_al_2005_SB.pdf]

External links

* [http://www.cnah.org/pdf_files/237.pdf PLESTIODON: A replacement name for most members of the genus EUMECES in North America, .pdf]
* [http://www.iczn.org International Commission on Zoological Nomenclature]