North American Recent Soft-shelled Turtles (Family Trionychidae) Part 12

asper_ differs from _pallidus_, _guadalupensis_ and _emoryi_ in having blackish spots and ocelli on the carapace, and lacking whitish dots or tubercles. _T. s. asper_ resembles _spinifer_, _hartwegi_ and _pallidus_ but differs from _guadalupensis_ and _emoryi_ in having conical tubercles along the anterior edge of the carapace in large females. For additional differences see accounts of other subspecies.

Of the subspecies of _T. spinifer_, _asper_ has a proportionately wide head that is closely approached in the subspecies _guadalupensis_ and _emoryi_; _T. s. asper_ differs from _guadalupensis_ and _emoryi_ in having a wider carapace, and resembles _hartwegi_ and _spinifer_, but differs from the other subspecies in having the carapace widest at a plane approximately one-half way back on the carapace. _T. s. asper_ differs from the other subspecies in having the shortest plastron.

_Remarks._--Stejneger (1944:72-74) has discussed the history of Baur's _Platypeltis aga.s.sizi_. Briefly, Aga.s.siz's description of _Platypeltis ferox_ wherein he (1857:402) states that "The young ferox [Pl. 6, fig.

3] has two or three concentric black lines separating the pale margin ...," was applicable to _T. s. asper_. Aga.s.siz mentioned also that the young of his _Aspidonectes asper_ (_op. cit._:406) "as in Platypeltis ferox, ... has ... two or three black lines separating the pale rim of the posterior margin, ..."; however, _A. asper_ was distinguished chiefly by the "... prominent warts of the bony plates (_loc. cit._)."

Because the description of the pattern of _ferox_ resembled that of _asper_, the validity of _asper_ was not agreed upon by all workers.

Boulenger (1889:245, footnote 1) referred to _asper_ as a species that required "... further investigation."

Baur (1888:1121) realized that Aga.s.siz's description of _ferox_ was not that of _Testudo ferox_ Schneider, and regarded the description of Aga.s.siz as applying to a new species, which he named _Platypeltis aga.s.sizii_; Baur (_op. cit._:1122) also recognized _asper_, referring it to the genus _Aspidonectes_. Baur designated a specimen from Georgia (the only individual seen by him) as the type of _aga.s.sizi_ (Stejneger, _op. cit._:73, footnote); this specimen is now MCZ 37172. Five years later (1893:218), Baur discussed generic relations.h.i.+ps of trionychids, seemingly only on the basis of skulls (holotype of _aga.s.sizi_ not mentioned), and referred _aga.s.sizi_ to the resurrected genus _Pelodiscus_ Fitzinger, 1835, which was distinguished from the other two American genera that Baur recognized (_Platypeltis_ and _Amyda_) by having the "Posterior nares reduced in size by the inner and posterior extension of the maxillaries." Baur also transferred _asper_ to the genus _Platypeltis_, and restricted the type locality of that species to "Lake Concordia, La." (_op. cit._:220); the type locality of _aga.s.sizi_ was restricted to "Western Georgia" (_loc. cit._).

The name-combination, _Pelodiscus aga.s.sizi_, was not generally accepted.

Hay (1892:144) and Siebenrock (1924:188) referred _aga.s.sizi_ to the genus _Trionyx_. Hay regarded _aga.s.sizi_ as a full species (see discussion by Stejneger, 1944:73), whereas Siebenrock considered it a subspecies of _spiniferus_; both authors regarded _asper_ as a synonym of _aga.s.sizi_. Neither _asper_ nor _aga.s.sizi_ was mentioned in the first three editions of the Check List of North American Amphibians and Reptiles (Stejneger and Barbour, 1917, 1923, 1933); the same authors in the fourth (1939:171, 172) and fifth editions (1943:212, 213) listed _aga.s.sizi_ as a full species, and _asper_ as a subspecies of _spinifera_. Stejneger (1944) used the same arrangement as set forth in the fourth and fifth editions of the Check List, and distinguished _aga.s.sizi_ on the basis of cranial characters, namely, the small size of the internal choanae, the greater width of the alveolar surface of the lower jaw, and the position of the suture between the palatine and basisphenoid relative to the posterior edge of the temporal fossa. Neill (1951:9) regarded the peculiarities of the _aga.s.sizi_-type skull as inconstant, but recognized _aga.s.sizi_ (and _asper_) as a subspecies of _ferox_. Crenshaw and Hopkins (1955) showed that _asper_ did not intergrade with _ferox_. Schwartz showed that _aga.s.sizi_ did not intergrade with _ferox_, and regarded _aga.s.sizi_ as a synonym of _T. s.

asper_ (1956:17), but stated that _aga.s.sizi_ possessed "wider crus.h.i.+ng surfaces on the maxillae than does _T. s. asper_, even when skulls of the same size and s.e.x are compared" (_op. cit._:9).

The holotype of _Platypeltis aga.s.sizi_ (MCZ 37172) is a dried adult female consisting of sh.e.l.l, skull and limb bones; the carapace is approximately 300 millimeters long (Schwartz, _loc. cit._). I have examined only the skull of MCZ 37172 (Plate 54), and it is the largest of 12 _aga.s.sizi_-type skulls I have seen. The basicranial length is 72.5 millimeters, and the greatest width, which occurs at the level of the quadratojugals, is 52.9 millimeters. The _aga.s.sizi_-type skulls have been discussed under the subsection on variation.

The type locality of _T. s. asper_, Lake Concordia, Louisiana (lower Mississippi River drainage) as restricted by Baur (1893:220), is in an area of intergradation of three subspecies of _Trionyx spinifer_ where most individuals are not typical of _asper_. The syntypes, the designation of MCZ 1597 as a lectotype, and Pearl River, Columbus, Marion County, Mississippi, as the type locality have been discussed elsewhere (Webb, 1960).

The range of _T. s. asper_ overlaps that of _T. ferox_ in Georgia and South Carolina. The two species remain distinct in the area of overlap of their geographic ranges (Crenshaw and Hopkins, 1955:16; Schwartz, _op. cit._:5). _Trionyx s. asper_ intergrades with _T. s. hartwegi_ and _T. s. spinifer_ in the lower Mississippi Valley (Conant and Goin, 1948:11).

However, there are few specimens available that indicate intergradation of _asper_ with the _spinifer-hartwegi_ complex in the lower Mississippi River drainage; this may be due to the fact that _asper_ inhabits waterways that do not drain into the Mississippi River. Perhaps intergradation is more prevalent than the morphological basis that I have relied upon indicates; in any event, there are few specimens that have more than one dark marginal line (which is the only character that is unique for _asper_) from the lower Mississippi drainage. A young male (TU 11928.9) from Bayou Gauche between Paradis and Des Allemands, St.

Charles Parish, Louisiana, has a pattern on the carapace resembling that of _asper_; several other small softsh.e.l.ls (TU) are available from the same locality but none shows more than one dark marginal line. Another specimen (USNM 95192), a young female from a barrow pit of the Big Black River (Mississippi River drainage), Madison County, Mississippi, resembles _asper_ in having more than one marginal ring. Of three large females from Moon Lake, an ox-bow of the Mississippi River in Coatopa County, Mississippi (AMNH 5285-86, 5289), only 5289 shows evidence of two marginal lines. USNM 73669 (Greenwood, LeFlore County, Mississippi) also indicates intergradation in that the spots tend to be linear just inside the dark marginal line, but the specimen more closely resembles the _hartwegi-spinifer_ complex rather than _asper_.

There seems to be little adumbration of the dark marginal lines of _asper_ in populations from the lower Mississippi River drainage.

Blackish spots and ocelli vary in size and there are many kinds of pattern on the carapace. Soft-sh.e.l.led turtles inhabiting the Mississippi River and its tributaries in Louisiana and Mississippi certainly represent an intergrading population of _spinifer_ and _hartwegi_, and, to a lesser extent, of _asper_. Soft-sh.e.l.led turtles inhabiting the Pearl River drainage and rivers that drain into Lake Pontchartrain immediately adjacent to the east are predominantly _asper_.

Specimens having localities from the Pearl River and Lake Pontchartrain drainages are listed under the account of _asper_ and are referred to that subspecies on the distribution map; specimens from the Mississippi drainage in Mississippi are referred to _spinifer_.

One specimen (UMMZ 59198, Bradley County, Tennessee), from the Tennessee River drainage where _T. s. spinifer_ occurs, deviates markedly from _spinifer_ and suggests intergradation. UMMZ 59198, plastral length 4.8 centimeters, has ocelli in the center of the carapace only two millimeters in diameter, a distinct but interrupted, second marginal ring consisting of spots, and the pale postl.a.b.i.al and postocular stripes in contact on both sides of the head.

_Specimens examined._--Total 110, as follows: ALABAMA: _Barbour_: UMMZ 113038, Chattahoochee River, Eufala. _Cherokee_: ANSP 24592, "near"

center of Terrapin Creek. _Conecuh_: UMMZ 70736, Murder Creek, Castleberry. _Escambia_: TU 15823, Escambia River, 1 mi. N Sardine; UMMZ 70734, Escambia River at Flomaton. _Henry_: TU 15630, 3 mi. NW jct. Echo Farm Rd. and Rt. 136 on Echo Farm Rd. _Lowndes_: UMMZ 67759, Pintlalla Creek. _Mobile_: MCZ 1608 (2), 1608A, Mobile. _Sumpter_: USNM 83996, 3 mi. SE Coatopa. _Tuscaloosa_: TU 14673 (5), Black Warrior River, 17.5 mi. SSW Tuscaloosa; UA 52-1085, Cottondale. _Walker_: KU 50843, 50851, TU 17137, Mulberry Fork, Black Warrior River, 9 mi. E Jasper.

FLORIDA: _Calhoun_: KU 50837-38, Chipola River, 4 mi. N Scott's Ferry; TU 16689 (4), Chipola River "near" Blountstown. _Escambia_: TU 13474, 15869 (3), 16584, Escambia River, 1.2 mi. E Century. _Okaloosa_: TU 15661, Blackwater River, 4.3 mi. NW Baker on Route 4. _Santa Rosa_: AMNH 44621, Blackwater River, Milton. _Walton_: UMMZ 110421, Pond Creek, 4 mi. SW Florala, Covington County, Alabama.

GEORGIA: _Baker_: TU 15889 (3), USNM 134243-48, Flint River "near"

Newton; USNM 30822. _Baldwin_: USNM 8708, Milledgeville. _Bryan_: TU 15090, Canouche River, 2.3 mi. W Groveland. _Chatham_: USNM 51981, 92583-84, Savannah. _Chattooga_: UMMZ 113037, tributary of Chattooga River, Lyerly. _Decatur_: KU 50839-42, Flint River, 1.5 mi. S Bainbridge. _Fulton_: UMMZ 53037, Roswell. _Lincoln_: USNM 91282-83, above Price Island, Savannah River. _Murray_: UMMZ 59196, 9 mi. N Spring Place. _Pulaski_: TU 14882, Ocmulgee River, 4.3 mi. SE Hawkinsville.

_Richmond_: USNM 66859, Augusta. _Whitfield_: UMMZ 74209, Cohulla Creek, Prater's Mill "near" Dalton. _County unknown_: MCZ 37172; UMMZ 109864, Flint River at mouth of Dry Creek; USNM 029034.

LOUISIANA: _East Baton Rouge_: LSU 11, 1643-44, City Park Lake in Baton Rouge; TU 17237, Amite River "near" Baton Rouge. _St. Tammany_: TU 6356, headwater creek of Bayou Lacombe; TU 16071, USNM 66147, mouth of Tchefuncta Creek in Lake Pontchartrain. _Tangipahoa_: TU 13623, 3.1 mi.

W Hammond; USNM 68054, Robert. _Was.h.i.+ngton_: KU 50840, 50846, TU 17117, Pearl River at Varnado. _Parish unknown_ (East Baton Rouge or Tangipahoa): UMMZ 95614, Manchac.

MISSISSIPPI: _Chickasaw_: USNM 115981, Chookatonkchie Creek. _Clarke_: USNM 79350-51, 1 mi. W Melvin, Choctaw County, Alabama; USNM 100805, Enterprise. _Forrest_: WEB 55-586, 1 mi. S Hattiesburg. _Hanc.o.c.k_: AMNH 46780; WEB 54-651, Hickory Creek "near" Kiln. _Lauderdale_: UMMZ 74681, 9 mi. W Meridian; UMMZ 90130, Lake Juanita, 15 mi. W Meridian.

_Lawrence_: KU 47120, TU 17307.1, Pearl River, 9 mi. S Monticello; USNM 7653-54, Pearl River at Monticello. _Lee_: CM 31904, Verona; USNM 115979, Cower's Area near Guntown. _Madison_: USNM 95191, 95193-94, Pearl River. _Marion_: MCZ 1597, Pearl River at Columbus (designated type locality). _Pearl River_: CM 21100, Pearl River, 20 mi. W Poplarville; TU 14362, Hobolochito Creek, 1 mi. N Picayune. _Perry_: WEB 55-580, Beaver Dam Creek, 1 mi. N Richton. _Walthall_: KU 50844, Bogue Chitto River, Dillon.

SOUTH CAROLINA: _Abbeville_: USNM 7650, Abbeville? (reported by Pickens, 1927:113; locality considered in error by Stejneger, 1944:50; USNM 7650 having only one dark marginal line paralleling rear margin of carapace is possibly an aberrant specimen--see page 495 of present account).

_Greenwood_: USNM 71681, 73668, Greenwood. _McCormick_: USNM 91310-12, Savannah River, 5 mi. W Plum Branch; USNM 92521, near Parksville.

_Richland_: AMNH 70724-25, Broad River, Columbia.

NO DATA: USNM 8359 (erroneously reported from Madison, Indiana by Yarrow, 1882:29 and Hay, 1892:145; see discussion by Cahn, 1937:200, and Stejneger, 1944:73-75); USNM 131859.

_Records in the literature._--ALABAMA: _Coffee_: Elba (KKA). _Marengo_: Tombigbee River near Demopolis. _Mobile_: Fig Island (Loding, 1922:47).

FLORIDA: _Jackson_: Chattahoochee River, 8 mi. SE Butler. _Leon_: Ochlocknee River, NW of Tallaha.s.see (Goin, 1948:304).

GEORGIA: _Bartow_: Etowah River below Allatoona Dam, _ca._ 4 mi. ESE Cartersville (Crenshaw and Hopkins, 1955:15). _Berrien_: (Knepton, 1956:324). _Emanuel_: Ogeeche River (Schwartz, 1956:19). _Fulton_: Nancy Creek, Atlanta (Dunston, 1960:278). _Gwinnett_: _Irwin_: (Knepton, _loc.

cit._). _Jenkins_: Ogeeche River near Buckland Creek jct., 2.5 mi. S Millen. _Liberty_: Camp Stewart, 4 mi. N Hinesville. _Morgan_: Lake Rutledge (Schwartz, _loc. cit._). _Muscogee_: Columbus (Stejneger, 1944:52). _Wayne_: Altamaha River, 5 mi. N Mt. Pleasant (Schwartz, _loc.

cit._). _Wilc.o.x_: Ocmulgee River, 3-4 mi. SSE Abbeville (Crenshaw and Hopkins, _op cit._:16, footnote; Schwartz, _loc. cit._).

MISSISSIPPI: _George_: Whiskey Creek (Cook, 1946:185). _Harrison_: near Biloxi. _Jackson_: Pascagoula Swamp, _ca._ 40 mi. E. Biloxi (Corrington, 1927:101). _Jones_: Eastabuchie. _Lee_: Cain Creek Bottom. _Lincoln_: Old Brook Creek. _Lowndes_: Tombigbee River, Camp Henry Pratt and Columbus; Lake Park, Columbus. _Pearl River_: 21 mi. SW Poplarville; 10 mi. W Poplarville; 4 mi. W Poplarville. _Wayne_: Trigg Area (Cook, _loc.

cit._).

NORTH CAROLINA: _Mecklenburg_: Catawba River near Charlotte (Schwartz, 1956:20).

SOUTH CAROLINA: _Aiken_: Savannah River, 10 mi. SW Jackson. _Allendale_: Savannah River, Fennell Hill, 2 mi. S US 301. _Anderson_: Pendleton.

_Bamberg_: South Edisto River, Cannon's Bridge, 5 mi. from Bamberg.

_Berkeley_: 2.5 mi. W Pinopolis. _Charleston_: Charleston. _Clarendon_: Upper Lake Marion at US 301; Lake Marion, 13 mi. SW Manning; 3.3 mi. S Jordan; 6.3 mi. S Jordan; Wyboo Creek, 8.5 mi. from Manning. _Colleton_: Edisto River (Schwartz, 1956:19-20). _Darlington_: Pee Dee River, Society Hill (Stejneger, 1944:72). _Dorchester_: Edisto River, 17 mi.

from Summerville; Edisto River, 14 mi. W Summerville; Edisto River, 2.5 mi. S Hart's Bluff. _Fairfield_: 1 mi. N Peak, Newberry County.

_Georgetown_: North Santee River, 1 mi. above US 17. _McCormick_: Little River near McCormick; Little River, 3 mi. NE Mt. Carmel. _Laurens_: Enoree River, 3 mi. S Cashville, Spartanburg County; Enoree River, 9.4 mi. N Clinton. _Orangeburg_: Edisto River, Orangeburg. _Saluda_: Batesburg; Lake Murray; Little Saluda River; 5 mi. from Saluda. _County unknown_: Upper Lake Santee (Schwartz, _loc. cit._).

=Trionyx spinifer emoryi= (Aga.s.siz)

Texas Spiny Softsh.e.l.l

Plates 43, 44

_Aspidonectes emoryi_ Aga.s.siz (in part), Contr. Nat. Hist. United States, Vol. 1, Pt. 2, p. 407; Vol. 2, Pt. 3, pl. 6, figs. 4-5, 1857.

_T[rionyx] s[pinifer] emoryi_ Schwartz, Charleston Mus. Leaflet, No. 26, p. 11, 1956.

_Type._--Lectotype, USNM 7855; alcoholic (s.e.x undetermined); obtained from the Rio Grande near Brownsville, Texas, in the course of the Mexican Boundary Survey under the command of Colonel Wm. H. Emory.

_Range._--Southwestern United States and northern Mexico; the Rio Grande drainage in Texas, New Mexico and northern Mexico; the Rio San Fernando and Rio Purificacion drainages in northeastern Mexico; the Colorado River drainage in Arizona, New Mexico, and southern Nevada (see map, Fig. 19).

_Diagnosis._--Juvenal pattern of white dots, not encircled with dusky or blackish ocelli, confined to posterior third of carapace; pale rim of carapace conspicuously widened, four to five times wider posteriorly than laterally; a dark triangle in front of eyes, base line connecting anterior margins of orbits; pale postocular stripe interrupted leaving conspicuous pale, usually dark-bordered, blotch just behind eye.

_Description._--Plastral length of smallest hatchling, 2.5 centimeters (USNM 7632); of largest male, 13.0 centimeters (KU 2914, 3125, 3150); of largest female, 22.0 centimeters (TNHC 8023, 8104).

Carapace pale brownish or tan, lacking whitish dots on anterior half; whitish dots confined to posterior third of carapace, sometimes lacking posteriorly, especially on juveniles; small, blackish dots rarely occurring on surface of carapace, usually confined to margins when present; pale rim of carapace four to five times wider posteriorly than laterally.

Pattern on snout rarely variable, consisting of pale stripes extending forward from eyes that have only their outer borders darkened and a straight or slightly curved, dark line that connects anterior margins of orbits; few, if any, dark markings in subocular and postl.a.b.i.al region; pattern on side of head having few contrasting marks, often of nearly uniform coloration; postocular stripe usually interrupted; anterior segment of postocular stripe just behind eye usually dark-bordered; posterior segment usually not dark-bordered or sharply distinguished from background; pattern on dorsal parts of soft parts of body contrasting, of relatively small dark marks; dark streaks often coincident with digits.

Underparts whitish, occasionally having blackish dots or smudges on posterior part of carapace, in region of bridge, or on lateral parts of chin and throat; few dark marks often on webbing of limbs and on palms and soles.

Small, flattened or wartlike, tubercles that occasionally have sharp tips along anterior edge of carapace on adult males; tubercles flattened, scarcely elevated, never conical along anterior edge of carapace on large females; whitish, k.n.o.blike tubercles often present posteriorly in middle of carapace and in nuchal region on large females; mottled and blotched pattern sometimes contrasting on carapace of large females; whitish dots of juvenal pattern often visible through overlying blotched pattern of large females.

Ontogenetic variation in PL/HW, mean PL/HW of specimens having plastral lengths 7.0 centimeters or less, 3.68, and exceeding 7.0 centimeters, 5.19; ontogenetic variation in CL/CW, mean CL/CW of specimens having plastral lengths 8.5 centimeters or less, 1.17, and exceeding 8.5 centimeters, 1.27; mean CL/PCW, 2.18; mean HW/SL, 1.43; mean CL/PL, 1.37.