''Plestiodon anthracinus'', the coal skink, is a

species A species () is often defined as the largest group of organisms in which any two individuals of the appropriate sexes or mating types can produce fertile offspring, typically by sexual reproduction. It is the basic unit of Taxonomy (biology), ...

of lizard which is

endemic Endemism is the state of a species being found only in a single defined geographic location, such as an island, state, nation, country or other defined zone; organisms that are indigenous to a place are not endemic to it if they are also foun ...

to the

United States The United States of America (USA), also known as the United States (U.S.) or America, is a country primarily located in North America. It is a federal republic of 50 U.S. state, states and a federal capital district, Washington, D.C. The 48 ...

Description

It is a mid-sized lizard with short well developed legs, and overlap when addressed in most specimens, except gravid females. It grows to in total length with a maximum snout-to-vent length (SVL) of . It is a four-lined

skink Skinks are a type of lizard belonging to the family (biology), family Scincidae, a family in the Taxonomic rank, infraorder Scincomorpha. With more than 1,500 described species across 100 different taxonomic genera, the family Scincidae is one o ...

whose light stripes extend onto the tail. The broad dark lateral stripe is 4–4.5 scales wide and there are no light lines on top of the head. The dorsolateral light stripe is on the edges of the 3rd and 4th scale rows, counting from midline of back. One postmental scale is present. The sides of the head of the male are reddish during spring breeding season, at least in some parts of the range.

Taxonomy

Two

subspecies In Taxonomy (biology), biological classification, subspecies (: subspecies) is a rank below species, used for populations that live in different areas and vary in size, shape, or other physical characteristics (Morphology (biology), morpholog ...

of the coal skink are recognized, including the

nominotypical subspecies In biological classification, subspecies (: subspecies) is a rank below species, used for populations that live in different areas and vary in size, shape, or other physical characteristics ( morphology), but that can successfully interbreed. ...

: *Northern coal skink – ''Plestiodon anthracinus anthracinus'' Baird, 1850 *Southern coal skink – ''Plestiodon anthracinus pluvialis'' ( Cope, 1880) The (northern) coal skink was first described by Baird in 1850; the southern subspecies ''P. a. pluvialis'' was identified by Cope in 1880. They are the near the ancestral form for the fasciatus group. The southern coal skink as a subspecies has posterior supralabials with light centers and dark edges, producing a spotted appearance. There are 26 or more rows of scales around the middle of the body.

Reproduction

The coal skink mates in spring or early summer, laying a clutch of 8 or 9 eggs. Their eggs are typically around 10–11 mm in length. Courting for this species usually involves the male's initial investigation and recognition of a potential female through pheromonal cues. The young hatch after four to five weeks and are about long. The hatchlings have a blue tail; those of the northern coal skink are striped like the adults, but young southern coal skinks have black bodies with at the utmost faint traces of stripes.

Habitat and Geographic range

Coal skink distribution

The more humid portions of wooded hillsides with abundant leaf litter or loose stones are favorite habitats. Coal skinks' habitat may also include areas around springs, rocky bluffs overlooking creek valleys, and mesic sites. If pursued, they will take refuge in shallow water, going to the bottom and hiding under stones or debris. The northern coal skink (blue in the figure) occurs in western New York and central

Pennsylvania Pennsylvania, officially the Commonwealth of Pennsylvania, is a U.S. state, state spanning the Mid-Atlantic (United States), Mid-Atlantic, Northeastern United States, Northeastern, Appalachian, and Great Lakes region, Great Lakes regions o ...

and in isolated colonies in the Appalachians. The southern coal skink (orange) can be found on the eastern Gulf coast from the

Florida Florida ( ; ) is a U.S. state, state in the Southeastern United States, Southeastern region of the United States. It borders the Gulf of Mexico to the west, Alabama to the northwest, Georgia (U.S. state), Georgia to the north, the Atlantic ...

panhandle to

Louisiana Louisiana ( ; ; ) is a state in the Deep South and South Central regions of the United States. It borders Texas to the west, Arkansas to the north, and Mississippi to the east. Of the 50 U.S. states, it ranks 31st in area and 25 ...

as well as west of the

Mississippi Mississippi ( ) is a U.S. state, state in the Southeastern United States, Southeastern and Deep South regions of the United States. It borders Tennessee to the north, Alabama to the east, the Gulf of Mexico to the south, Louisiana to the s ...

from eastern

Kansas Kansas ( ) is a landlocked U.S. state, state in the Midwestern United States, Midwestern region of the United States. It borders Nebraska to the north; Missouri to the east; Oklahoma to the south; and Colorado to the west. Kansas is named a ...

and central

Missouri Missouri (''see #Etymology and pronunciation, pronunciation'') is a U.S. state, state in the Midwestern United States, Midwestern region of the United States. Ranking List of U.S. states and territories by area, 21st in land area, it border ...

to eastern

Texas Texas ( , ; or ) is the most populous U.S. state, state in the South Central United States, South Central region of the United States. It borders Louisiana to the east, Arkansas to the northeast, Oklahoma to the north, New Mexico to the we ...

and northern Louisiana. Scattered intermingled occurrences of both subspecies (green in the figure) occur in

Alabama Alabama ( ) is a U.S. state, state in the Southeastern United States, Southeastern and Deep South, Deep Southern regions of the United States. It borders Tennessee to the north, Georgia (U.S. state), Georgia to the east, Florida and the Gu ...

and in Georgia. Their current natural threats include a number of small mammals, snakes, and larger species of lizards. Human influence has also been known to pose a threat to this species, due to habitat decrease and degradation for a number of reptile species.

References

External links