Anniella pulchra GRAY, 1852
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Higher Taxa | Anguidae (Anniellinae), Diploglossa, Anguimorpha, Sauria, Squamata (lizards) |
Subspecies | |
Common Names | E: California Legless Lizard S: Lagartija Ápoda pulchra: Silvery Legless Lizard, S: Apoda Plateada nigra: Black Legless Lizard, S: Apoda Negra |
Synonym | Anniella pulchra GRAY 1852: 440 Anniella pulchra — BOULENGER 1885: 299 Anniella nigra FISCHER 1885: 9 Anniella nigra — BOULENGER 1885: 300 Anniella texana BOULENGER 1887: 50 Anniella pulchra pulchra — GRINNELL & CAMP 1917: 170 Anniella pulchra pulchra— SMITH & TAYLOR 1950: 209 Anniella nigra nigra — HUNT 1983 Anniella pulchra pulchra — STEBBINS 1985: 168 Anniella pulchra — STEBBINS 1985: 168 Anniella pulchra — LINER 1994 Anniella pulchra nigra — CROTHER 2000: 31 Anniella pulchra— PIANKA & VITT 2003: 27 Anniella pulchra pulchra — COLLINS & TAGGART 2009 Anniella pulchra nigra — COLLINS & TAGGART 2009 Anniella pulchra — CROTHER et al. 2012 Anniella pulchra — PAPENFUSS & PARHAM 2013 |
Distribution | USA (CW/SW California) pulchra: Pacific slopes of C/S California; Type locality: California. Restricted to San Diego, by SMITH & TAYLOR 1950. Neotype locality: Pinnacles National Monument, San Benito County, California. nigra (invalid): Type locality: Near San Diego, California, USA. |
Reproduction | ovovivparous |
Types | Neotype: MVZ 64656, designated by Murphy and Smith 1991; Holotype: was BMNH 52.4.12.3; the holotype of A. pulchra was shown to be A. geronimensis by Hunt 1983 who also (temporarily) synonymized geronimensis with pulchra. Syntypes: lost, originally ZMH fide HALLERMANN 1998, leg. J. BEHRENS [nigra] |
Diagnosis | DEFINITION (genus). These are small, fossorial, limbless lizards (adult SVL 90–170 mm, tail length 34–103 mm (30%–42% of total length). Both species are viviparous. Size differences, dichromatism, or other external sexual dimorphism is absent. This lizard exhibits a number of morphological specializations for burrowing, including: an elongate, subcylindrical body, slightly concave ventral surface, a cylindrical tail that tapers to a blunt tip, diminutive eyes with a movable, semi-transparent lower lid, no external limbs, no external ear openings, a wedge-shaped head in profile, a shovel-shaped snout, a strongly countersunk lower jaw, smooth, cycloid dorsal and ventral body scales, roughly uniform in size, and caudal scales larger than body scales. The head is covered with large, irregular scutes. The interclavicle element of the pectoral girdle is vestigial or lost entirely in adults (see Comment). The pelvic girdle is vestigial, consisting of a pair of rod-shaped ilia. The left lung and left oviduct are vestigial. The tongue is bilobed, villose, and attached medially along its entire length. The lateral nasal gland is greatly developed and the configuration of the walls of the vestibule and nasal valve permit complete occlusion of the nares while burrowing. Dorsal color varies significantly within and between species, ranging from jet black and dark brown in some coastal populations to copper, tan, olive, grey, and metallic silver in other coastal populations and interior populations (see species accounts). Ventral color varies from pale yellow to bright yellow to greyviolet. A black or brown vertebral stripe and one or more lateral stripes are present in most populations. The lateral stripes coalesce along the sides of the head to form an eye stripe in some populations. Brown or brownish-black pigment surrounds the ventral scales on the tail, forming faint or distinct zigzag stripes between the scale rows. There are 68–81 procoelous presacral (dorsal) vertebrae, 3–4 (typically 3) sacral vertebrae, and 36–59 postsacral (caudal) vertebrae. The caudal chevrons are fused to the centra, and the branches unite to form a common stem. The first 3–4 caudal vertebrae lack the chevron bones and fracture planes that are present in more distal vertebral elements. The cranium is adapted for burrowing and is characterized by thickened, closely knit, or fused elements, a short snout, and expanded occipital and temporal regions of the braincase. The frontoparietal suture provides mesokinetic flexion. The mandible is shorter than the skull and is inset. The retroarticular process of the mandible is widened posteriorly and twisted. The teeth are subpleurodont, recurved, fang-like, and have a mediodorsal groove. There are 4–5 premaxillary teeth and 4–7 (usually 7) maxillary teeth, separated by a diastema. Palatine and pterygoid teeth are absent. The mandible has five bones and supports 7–8 dentary teeth. The braincase is closed laterally by descending wings of the parietals and posteriorly by an interlocking suture between the prootic and parietal bones. The postorbital bone does not enter the orbit. The skull is streamlined by loss of the upper temporal arch, postorbital arch, and squamosal and strong reduction of the jugal with little or no angulation. An interorbital septum is present. There is no parietal foramen, but there is a cavity near the anterior edge of the fused parietals that contains the parietal eye. The frontals unite ventrally to form a complete subolfactory arch. Small, thin dorsal and ventral osteoderms are present on the body and tail, and cranial osteoderms are absent. Basipterygoid processes are present, the epipterygoids are reduced in size, and the interpterygoid vacuity is well developed. The palatine has extensive choanal grooves, the maxilla broadly overlaps a single premaxilla, and a premaxillary foramen is absent. The vomers are broad. The quadrate is short and inclined forward. There is a single hyoid arch, the hypohyals are cartilaginous and not fused to the basihyals, the ceratohyals are absent, and a geniomyoideus muscle is present. The tympanic membrane and eustachian tubes are absent and the middle ear is replaced by lymph cavities. The columella is reduced to a large footplate that occupies the entire lateral wall of the otic capsule. A cartilaginous extracolumella is firmly embedded in the quadrate. The ciliary tufts of the hair cells are bidirectionally oriented (from Hunt 2008). DEFINITION (species). Anniella pulchra is a small, elongate, fossorial, limbless lizard (adult SVL 95–170 mm, tail length 43–103 mm, tail 26%–42% of total length). Sexual dimorphism and dichromatism are absent. The snout is rounded in profile, there are 24– 34 body scale rows at mid-body, 5–8 (typically 7) supralabials with the second supralabial scale being the largest, 4–8 scale rows between the vertebral and first lateral stripe, and 84–130 scales along the vertebral midline on the tail. Color, pattern, body size, and scalation vary geographically (Hunt 1984). Populations inhabiting coastal dunes fringing southern Monterey Bay and on the Monterey Peninsula in Monterey County display a dark brown to jet-black dorsum and a relatively short tail (as a percentage of total length). Coastal populations from southwestern San Luis Obispo and western Santa Barbara County also display a dark brown dorsum, but are not jet-black and have relatively longer tails. Dorsal coloration in other coastal and interior populations ranges from metallic silver, silvery-green, copper, tan, to beige. Ventral coloration varies from whitish-yellow to bright chrome yellow. One or more brown or black stripes separate the dorsum and ventrum along the side of the body. These stripes coalesce along the sides of the head to form an eye stripe in some populations. The preanal scales are tipped with brown or black and contrast with the surrounding solid yellow or whitish-yellow ventral body scales. A brown or brownish-black border occurs along the edges of the ventral tail scales, forming faint zigzag longitudinal stripes between the scale rows on the tail. A brown or black vertebral stripe is visible in most non-melanistic populations, although this may be faint or distinct (Hunt 2008). |
Comment | Subspecies: A. pulchra nigra, a melanic form restricted to two disjunct coastal populations may have arisen independently from different ancestral populations and is that not monophyletic. Many subsequent authors thus synonymized this subspecies with A. pulchra. Distribution: A. pulchra does not occur in Mexico where it is represented by A. stebbinsi (since the latter was split off from A. pulchra). See map in Hunt 2008. Type species: Anniella pulchra GRAY 1852 is the type species of the genus Anniella GRAY 1852. Note that A pulchra has been split up into 5 different species by PAPENFUSS & PARHAMM 2013. Anniella is also the type genus of the subfamily Anniellinae (sometimes considered as a family, Anniellidae, but the latter status would make if paraphyletic fide Zheng & Wiens 2016). |
Etymology | Named after Latin “pulcher” = beautiful, handsome, fine, fair. Limbless. The genus name was not explained by John Edward Gray, but he often created obscure or fanciful scientific names. It could be a given name, as the archaic Polish, Italian, and Spanish feminine cognates, ‘Aniella’ and ‘Anniella’, as well as the Christian feminine name, ‘Agnes’, are derived from the Latin noun “agnellus”, meaning little lamb. Beltz (2006) speculated the name could be a combination of the Latin noun ‘anulus’, meaning ring, and the feminine Latin diminutive ‘–ella’, meaning little, possibly referring to the cylindrical shape and small size of the body, or even a combination of the pet name Annie and the suffix ‘–ella’ (from Hunt 2008). |
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