With Comments on the Interrelationships of Gurgesiellidae and Pseudorajidae (Pisces, Rajoidei)

BULLETIN OF MARINE SCIENCE, 29(4): 530-553, 1979

A FURTHER DESCRIPTION OF GURGES/ELLA FURVESCENS WITH COMMENTS ON THE INTERRELATIONSHIPS OF GURGESIELLIDAE AND PSEUDORAJIDAE (PISCES, RAJOIDEI)

John D. McEachran and Leonard J. V. Compagno

ABSTRACT Additional specimens of Gurgesiella furveseens are used to supplement the original description which was based solely on the holotype. The clasper, neurocranium, pectoral girdle, and pelvic girdle of this species are described and compared with those of the only known congener, G. at/antiea, and with Pseudorajajiseheri. Comparisons support Hulley's (1972b) removal of G. atlantica from Pseudoruja to Gurgesiella. Gurgesiella and Pseudo/'aja share many character states which are considered to be derived within Rajoidei, negating the hypothesis that their resemblances are due to synplesiomorphies. Gurges;eJ/a resembles Allacanlhobalis and Cruriraja in clasper morphology and AllaCtlllthobatis, Cruriruja, Raja (Rioraja) and R. (At/an/oruja) in the structure of its scapulocoracoid. The scapulocoracoid of Pseudvraja resembles those of some Psammobalis species. Both genera possess reduced rostra, that of Gurgesiella was probably derived from an ancestor with a stout or partially reduced rostrum, while the rostrum of Pseudoraja is too reduced 10 determine if it was derived from the Gurgesiella type or from a more slender Iype. However, Gurgesiella and Pseudvruja share five derived characlers, which according to our present knowledge, are unique within Rajoidei. Thus, Gurgesiella and Pseudoraja appear to be a monophyletic group and their resemblances to other taxa can be explained by secondary relationships, parallelisms and retension of primilive character states. Similarilies in shared derived character states implies that separate families for Gurgesie//a and Pseudoraja arc unwarranted and Gurgesiellidae is merged with Pseudorajidae. Pseudorajidae, Pseudoraja and Gurgesie//a are redefined. The scapulocoracoid, not hitherto used in phylogenetic studies of Rajoidei, is introduced and appears to be an important taxonomic and phylogenetic character.

Despite a number of regional revisional studies of the family Rajidae within the last 20 years (Ishiyama, 1958; Stehmann, 1970, 1976; Hulley, 1972a) and several revisions of related families (Hulley, ]972b, ]973) the phylogenetic interrelationships within the suborder Rajoidei remain unclear. Hulley (1972a, 1972b) recognized six families, Rajidae Bonaparte, 1831, Anacanthobatidae von Bonde and Swart, 1924, Arhynchobatidae Fowler, 1941, Pseudorajidae Bigelow and Schroe- der, 1954, Gurgesiellidae de Buen, 1959, and Crurirajidae Hulley, 1972; while Compagno (1973) recognized four families, placing Gurgesiellidae in Pseudoraji- dae and Crurirajidae in Rajidae. Discordance in the higher classification of Ra- joidei is due to the erection of more recent families before determining the range of variability within the oldest and largest family, Rajidae (containing about 80% of the 185 to 199 species in the suborder), The five more recent families have been defined by a few unique, mostly external characters and other characters which are found within Rajidae. The unique characters include presence of or number of dorsal fins, structure of the caudal fin, shape and structure of the pelvic fin, presence of an oronasal pit, structure of the rostral cartilage, and structure of the pelvic girdle. These characters are important in distinguishing lower taxa (species, subgenera and possibly genera) but may not be as important as internal structures, i.e. cranial, pectoral girdle or clasper structure, in distinguishing the higher taxa (families). The status of the families and their interrelationships will not be clear until the variability within Rajidae has been determined on a world- 530 McEACHRAN AND COMPAGNO: TAXONOMIC STUDIES OF RAJOIDEI 531

wide basis. Prior to this monumental undertaking the anatomical characters which have proved valuable in determining the interrelationships within Rajidae must be described for the remaining five families. Recently we obtained several specimens of Gurgesiella furvescens, G. atlantica (Gurgesiellidae) and Pseudoraja fischeri (Pseudorajidae), including mature males of the two former species, and herein describe the anatomical characters of these species which have been important in elucidating rajid interrelationships. De Buen (1959) erected the family Gurgesiellidae for his new species, Gurge- siella furvescens, which he described from a single specimen captured off Val- paraiso, Chile. He distinguished Gurgesiellidae from Pseudorajidae Bigelow and Schroeder 1954, the latter of which he considered related to Myliobatoidei, largely on the structure of the pelvic fin. Bigelow and Schroeder (1962) described another pseudorajid, Pseudoraja atlantica, from the Caribbean Sea and stated that the characters on which Gurgesiellidae was based appeared to fall within Pseudora- jidae. Hulley (1972b) examined radiographs of the pelvic girdle and cranium of Pseudoraja fischeri, P. atlantica and Gurgesiella furvescens, concurred with Bigelow and Schroeder (1954, 1962) that Pseudorajidae was a member of Rajoidei but concluded that Gurgesiellidae should be maintained as a separate family and that P. atlantica should be placed in Gurgesiella.

MATERIALS AND METHODS

Specimens examined in this study were borrowed from the Stanford University Fish Collection (SU) housed at the California Academy of Sciences (CAS) San Francisco; Museum of Comparative Zoology (MCZ), Cambridge, Massachusetts: National Marine Fisheries Service Systematic Labora- tory (NMFS SL) Washington, D.C.; Smithsonian Oceanographic Sorting Center (SOSe) Washington, D.C. and National Museum of Natural History (USNM) Washington, D.C. A list of material examined follows the text. Methods of Bigelow and Schroeder (1953) were followed in making external measurements. Ver- tebrae were counted from radiographs according to methods described by Krefft (1968). All anatomical descliptions were based on dissected specimens but dissections were compared with radiographs because only one specimen per species was completely dissected. Removing the cranium, pectoral and pelvic girdles resulted in considerable damage to specimens and there are few available specimens of G. furl'escens and P. fischer;. Clasper terminology follows Stehmann (1970) and Hulley (1972a). Terminology of the cranium is modified from Hulley (1972a). Several of the terms of Hulley (l972a) for cranial foramina arc changed to be consistent with the usage of earlier authors, e.g. Daniel (1934). All cranial measurements except the following are from Hubbs and Ishiyama (1968). Nasobasal length: distance from anteromedial corner of nasal capsule, at side of rostrum, to posteromedial face of occipital condyle (Fig. la). Width across otic capsules: transverse axis of cranium, across lateral walls of otic capsule above hyomandibular facets and opisthotic Iidges and below sphenopterotic ridges. Least width of basal plate: wide of basal plate at its ventrolateral junction with orbital walls. Greatest width of nasal aperture: greatest transverse or diagonal dimension across nasal aperture (ventral aperture of nasal capsule). Internasal width: least distance across interspace between nasal apertures. Hulley (1972a) suggested that the cranial measurements and proportions proposed by Hubbs and Ishiyama (1968) were of little use. However, their utility is limited by Hubbs and Ishiyama's use of cranial length (anterior tip of rostral cartilage to rear end of cranium) as the independent variable in computing cranial proportions. Cranial length includes the highly variable rostral length, which ob- scures similarities and differences in post rostral proportions. Following usage in sharks (Compagno, ms.) we use nasobasal length as an independent variable in computing proportions, but define it slightly differently in batoids due to differences in cranial structure (in sharks the nasobasallength is measured to the rear of the occipital centrum). The measurements of the lateral face of the scapulocoracoid were made as follows: Greatest length: greatest distance from procondyle to metacondyle (Fig. Ib). Greatest height: greatest distance from scapular process to base of scapulocoracoid. Premesocondyle: greatest distance from procondyle to midpoint of mesocondyle. Postmesocondyle: greatest distance from midpoint of mesocondyle to metacondyle. Anterior fenestra width: greatest horizontal distance between anterior and posterior border of fenestra. Anterior fenestra height: greatest vertical distance between dorsal border of anterodorsal fenestra and ventral border of anteroventral fenestra (if anterior bridge is present) or greatest 532 BULLETIN OF MARINE SCIENCE, VOL. 29, NO.4, 1979 a {ftL 5

7 (f\~ iT14 ~~ I OQO a 0 I

--.~--9---

Figure I. a Ventral view of a rajoid neurocranium showing proposed measurements; b Lateral view of a rajoid scapulocoracoid showing proposed measurements. I = nasobasal length, 2 = width across otic capsules, 3 = least width of basal plate, 4 = greatest width of nasal aperture, 5 = internasal width, 6 = greatest length, 7 = greatest height, 8 = premesocondyle, 9 = postmesocondyle, 10 = postdorsal fenestra length, II = postdorsal fenestra height, 12 = anterior fenestra length, 13 = anterior fenestra height, 14 = height of rear corner. McEACHRAN AND COMPAGNO: TAXONOMIC STUDIES OF RAJOIDEI 533 vertical distance between dorsal and ventral border of anterior fenestra (if anterior bridge is lacking). Postdorsal fenestra length: greatest horizontal distance between anterior and posterior border of fenestra. Postdorsal fenestra height: greatest vertical distance between dorsal and ventral borders of fenestra. Height of rear corner: vertical distance between posterodorsal corner and base of scapulocoracoid. Greatest length of scapulocoracoid is used as the independent variable for proportional measurements.

Gurgesiella furvescens de Buen, 1959 Figure 2 Morphometry.-Proportions computed from measurements listed by de Buen (1959) for the holotype of G. furvescens are very close to or within the range of those computed from our 12 additional specimens except that the ratio of disc length to total length is less for the holotype (Table I). Description: Disc ranges 1.5 to 1.6 times as broad as long; maximum angle in front of spiracles 136° to 154°, greater in females and immature males; margin of disc convex from tip of snout to above level of spiracles then changing to concave from level of spiracles to outer corners which are abruptly rounded; posterior margins straight along lateral aspect but slightly convex along medial aspect. Tip of snout with a small triangular process. Axis of greatest width 63.4 to 79.5% of distance from tip of snout to axil of pectorals. Pelvic fins with posterior margins straight to weakly concave when spread; anterior margins 1.1 to 1.6 times as long as distance from origin of anterior lobe to posterior margin of fin, ratio less for mature males than for immature males and females. Tail slender, its width at midlength about one- half diameter of eye. Tail with a lateral fold along ventrolateral surface running from near level of posterior margins of pelvies to just posterior to origin of ventral lobe of caudal fin; fold gradually widens distally until it equals about two-thirds the height of dorsal lobe of caudal fin. Length of tail from center of cloaca to distal tip 1.7 to 2.1 times distance from tip of snout to center of cloaca. Preocular length 1.5 to 2.1 times as long as orbit; preoral length 1.3 to 1.6 times internarial distance. Interorbital distance 0.6 to 0.8 times length of orbit; orbit length 1.3 to 2.3 times as long as spiracle. Nasal curtain with few or no fringes; outer nasal flap with fine fringes; without oronasal pit. Upper and lower jaws moderately arched in females and immature males, strongly arched in mature males. Teeth with low cusps in females and immature males, with sharp pointed cusps in mature males; teeth in quincunx arrangement in females and immature males, teeth in more or less vertical rows in mature males. Upper jaw slightly indented at symphysis in females and immature males, strongly indented in mature males. Distance between first gill slits 2.1 to 2.6 times as great as between nares; distance between fifth gill slits 1.4 to 1.8 times as great as between nares; length of first gill slit 1.1 to 1.8 times length of fifth gill slit and 0.2 to 0.4 times mouth width. No dorsal fins. Base of dorsal lobe of caudal fin slightly less than preocular length, its maximum height 0.3 to 0.6 times diameter of eye; ventral lobe of caudal originating posterior to dorsal lobe, its base 0.7 to 0.8 times as long and its height 0.7 to 0.9 times as great as dorsal lobe; lobes not confluent at tip of caudal. Rostrum soft and flexible near tip; pectoral radials extend to near anterior tip of disc. Upper surface of disc and tail sparsely covered with small denticles on stellate bases. Ventral surface naked. Mature males with stout and sharp malar thorns along anterior margin of disc from anteriormost pectoral radial to level of anterior margin of orbit and with two or three rows of retractable alar thorns on outer corners of upper disc, alar rows follow contour of disc. 534 BULLETIN OF MARINE SCIENCE.VOL. 29. NO.4. 1979

Figure 2. Gtlrgesiella ftlrvescens. a, b. SOSC, ANTON BRUUN, Cr. 18A, LWK 66-44, mature male, 510 mm TL; dorsal and ventral views; c, d. SOSC, ANTON BRUUN, Cr. 18A, LWK 66-44, mature female, 569 mm TL, dorsal and ventral views.

Upper surface of disc chocolate brown with yellowish areas between anteriormost pectoral radials and orbits and over scapular region. Lower surface light grayish brown occasionally with a pale yellow area over center part of the disc from nares to posterior margin in pelvics. Mature males ranged from 509 to 520 mm TL while mature females ranged from 552 to 568 mm TL. The additional specimens of G. furvescens extend the range of this species McEACHRAN AND COMPAGNO: TAXONOMIC STUDIES OF RAJOIDEI 535

T.ble 1. G1Jr~sif!l18 fur-.:e,cenl, proportional measurements and counts compared with those of ~:1l.1.!!.!l-~E

Proportions in percent of lotallength. immcoimmature. mat"'rnature, j(=mean

Vilparaiso, Chile. 32" S. Peru::::'08Q S. Galapagos Islands

1 dmal 1fl'\i11 Ronge

Total Ll'"gth (mm) 303 320 331 337 384 440 509 520 552 568 476 479 372 188...154

54 53 52 52 58 56 57 52 55 58 55 59 58 55.4 46· 60 52.4

Oi~c Lf'nglh 35 35 34 34 35 34 38 31 35 37 37 38 38 35.5 31· 37 34.4

Snout Lrnqth (Preoculilrl 6.8 7· 10 8.6

SnOlJt L('n9fh (Preoral) 10 7.7 8· 11 9.4

$nOl..ll to M.))(imum Disc Width 23 21 22 21 25 22 24 20 23 24 23 22 22.5 20- 25 22.0

PrenJs.:!1 Lf'ngth 4.8 4.3 4.4 4.4 4.7 4.7 3.9 3.8 4.0 4.4 4.1 5.2 4.8 4.3· 7.0 5.6

Orbit DiamE'!cr 4.0 3.9 3.7 4.0 3.9 3.5 3.7 3.3 3.8 4.0 3.4 4.2 4.5 3.8 3.4- 4.5 4.1

DiS1Jm:lJBetween Orbiu 2.3 2.8 2.6 2.6 2.6 2.4 2.6 2.7 2.7 2.6 2.5 3.3 2.8 2.7 2.3- 3.0 2.6

Orbit ulld Spiracle Length 5.2 5.2 5.1 5.5 5.1 5.0 5.8 4.8 5.6 5.4 5.7 5.4 5.0 5.3 4.6· 5.7 5.0

1.9 2.0 1.9 2.J 2.1 2.1 1.B 1.9 2.1 J.8 2.5 2.5 2.2 2.1 1.6· 3.8 2.2

Distance Between Spiracles 5.1 5.2 5.1 5.1 5.1 4.7 5.5 5.3 5.5 5.5 6.1 5.8 5.3 4.9· 7.6 5.5

5.1 5.2 5.6 5.5 5.3 5.2 6.3 6.2 5.3 6.0 6.7 7.1 6.0 5.9 5.2· 7.0 5.8

DISlilnell Blllwcen Nostrils 4.9 5.2 5.2 5.2 5.0 5.0 5.1 !:i.o 11.9 5.1 5.0 5.6 6.1 5.2 4.0- 4.9 4.5

Width 01 First Gill Opening 1.4 1.6 1.6 1.7 2.0 1.8 1.6 1.2 1.6 1.8 1.7 2.1 1.4 1.6 1.0- 1.5 1.2

Width of Third Gilt Opening 1.5 1.8 1.7 1.8 1.8 1.9 1.6 1.0 1.7 1.6 1.7 1.7 1.6 1.6 1.0· 1.4 1.2

Width of Fifth Gill Opening 0.9 1.1 0.9 1.0 1.6 1.1 1.0 0.8 1.2 1.2 1.5 1.5 0.9 1.1 1.0· 1.1 0.9

DistJnctl Bt'lwecn First Gill Openings 12 12 13 12 12 12 12 12 12 13 13 14 12 12.5 g·11 10

DiSIJnCe BCl\\'Cen Filth Gill Oper'lIngs 7.8 6· 7 6.1

Lf'ngth of Anlf'rior Pcl\lic Lobe 11 12 11 11 12 11 14 13 11 13 14 13 12.3 g. 13 11.4

DislJncc . Snout to Clo.Jca 32 33 33 32 32 33 34 30 32 34 36 37 35 33.2 31· 34 32.6

Oistuncc . CloJc.;l to CJud.;ll Origin 63 63 64 54 61 62 60 61 60 57 57 58 60.5 58· 64 60.4

DistJncl' . CluJca to CJudJI Tip 68 67 68 68 67 68 65 67 68 86 64 63 65 66.3 65· 70 67.4

Number of Toolh Rows (Upper J'l\\l1 40 43 36 36 36 27 31 30 37 34 37 29 35.2 26· 44 36.8

Number of Trunk VNlcobr,)f! 22 22 22 21 23 22 23 23 22.5 23 23.0

Numbcr of PrecJudal Tilll Vertebr..lt,! 94 94 94 96 93 92 93 97 94.1 97· 99 97.3

1Holotypc, dJla from dll Buen 09591

from its type locality off Valparaiso, Chile (ca. 32°S) to off northern Peru (07°49'S) and the Galapagos Islands (Ol033'S). Specimens were captured at depths from 400 to 960 m. Gurgesiella furvescens closely resembles its only congener G. atlantica, from the tropical western Atlantic. However, G.furvescens has a proportionally shorter preocular and preoral distance (5.8 to 8.6 vs. 7.0 to 9.7 and 6.2 to 9.5 vs. 8.2 to I1.0), greater width of the third gill slits (1.5 to 1.9 vs. 1.0 to 1.4) and a greater distance between the first gill slits (11.8 to 14.0 vs. 9.3 to 11.3) than G. atlantica (Table I). Also in G. furvescens the ratio of preocular length to orbit length and preoral length to internarial distance is less than in G. atlantica. G. furvescens lacks middorsal thorns, is only sparsely covered with denticles on the dorsal sUlface and is naked on the ventral surface while G. atlantica possesses thorns 536 BULLETIN OF MARINE SCIENCE. VOL. 29. NO.4. 1979

lem pr

Figure 3. a, b. Right clasper of Gurgesie/la !urvescens sasc, ANTON BRUUN Cr. 18A, LWK 66- 44; a. dorsal view, b. lateral view opened to show components; c, d. right clasper of G. atlantica NMFS SL, Caribbean Sea; c. dorsal view, d. lateral view expanded; cf-cleft, fn-funnel, hy- hypopyle, pr-pseudorhipidion, rh-rhipidion, sh-shield, sp--spike, st-sentinel.

along the dorsal midline, is densely covered with denticles on the dorsal surface and possesses denticles on the ventral surface. Mature males of G. jurvescens possess acutely pointed malar thorns while mature males of G. atlantica possess malar thorns with smoothly rounded tips (Bigelow and Schroeder, 1962), although the latter may be a variable character (Bigelow and Schroeder, 1965). The upper surface of the disc and tail of G. furvescens is chocolate brown while that of G. atlantica is pale brown; and the lower surface of the former species is darker than that of the latter species. Male and female G. furvescens mature at a larger size than those of G. atlantica (509 to 520 vs. 390 to 393 mm TL and 552 to 568 vs. 442 to 489 mm TL respectively).

Anatomical Comparisons with Gurgesiella atlantica and PseudoraJa fischeri Claspers.-G. furvescens has very long and slender claspers, with ventral lobe splayed out at origin of glans; dorsal lobe only slightly expanded at origin of glans; distal end bluntly pointed (Fig. 3a); without dermal denticles; without pscu- dosiphon; inner dorsal lobe with cleft (Fig. 3b); pseudorhipidion medial to clcft, running about one-half length of glans, extended distally as flap of intcgument to about distal one-third of glans; inner ventral lobe with well developed shield, extending from level of hypopyle to level of spike, with lateral margin sharp- edged and naked and with transversely pleated integument ovcr proximal surface; sentinel well developed, located medial and distal to shield, rod-shaped, lateral margin with thick integument, terminating near tip of glans as a sharp point; small McEACHRAN AND COMPAGNO: TAXONOMIC STUDIES OF RAJOlDEI 537

a b ".. ".. ''"8

Qlr. dtr, o~, dtr. o~, .., ch" "'"

d e

lem ,.., '''0

--''"8 d..,

".. " .. d~. air, O~, dtr.

Figure 4. a, b, c. Right clasper cartilages of GlIrgesiella fllrvescens sasc, ANTON BRUUN, Cr. 18A, LWK 66-44; a. lateral view, partially expanded, b. dorsal view, c. ventral view; d, e, f. Right clasper cartilages of G. atlantica NMFS SL, Caribbean Sea; d, lateral view, partially expanded, e. dorsal view, f. ventral view; atrt-accessory terminal I cartilage, art2-accessory terminal 2 cartilage, ax- axial cartilage, dmg-dorsal marginal cartilage, dtr2-dorsalterminal 2 cartilage, dtr,,-dorsalterminal 3 cartilage, vmg-ventral marginal cartilage, vtr-ventral terminal cartilage.

rhipidion located on medial surface of sentinel, extending from origin of sentinel to level of integumentary flap of pseudorhipidion, with finely pitted surface; spike lying under sentinel, dorsoventrally flattened, with straight, sharp-edged and naked distal margin; and funnel located ventrolateral to midsection of sentinel, acutely pointed and covered with thick integument. Basal group of clasper cartilages consisting of basi pterygium, b1, b2, beta and axial cartilages arranged as in Rajidae, Crurirajidae, and Anacanthobatidae, b1 bears last four rays of pelvic fin, beta cartilage articulating with both axial and 538 BULLETIN OF MARINE SCIENCE, VOL. 29, NO.4. 1979 dorsal marginal cartilages; axial cartilage very slender distally, forming very slender tip (Fig. 4a), less calcified than other cartilages; dorsal marginal with long slender distomedial extension entering glans and forming pseudorhipidion, with concave outer distal margin articulating with dorsal terminal 2 and dorsal terminal 3 cartilages; ventral marginal with an S-shaped distal margin articulating with accessory terminal I and accessory terminal 2 cartilages; dorsal terminal I absent; dorsal terminal 2 small, comma-shaped, articulating with dorsal terminal 3 along its lateral border (Fig. 4b); dorsal terminal 3 elongate, distally very thin, articulating with dorsal marginal proximally and with dorsal terminal 2 proximomedi- ally, with a crenate distal margin; ventral terminal loosely attached to inner surface of accessory terminal I and distal inner surface of ventral marginal, slightly twisted laterally along its longitudinal axis, with lateral margin forming shield, distal extension forming funnel, with strap-like anterior notch at right angles to longitudinal axis wrapping around axial; accessory terminal I elongate, Y-shaped, with a long and a short proximal arm, with distal extension dorsoventrally flattened and forming sentinel (Fig. 4c); accessory terminal 2 dorsoventrally flattened, rod-shaped, articulating with short arm of accessory terminal] and distal margin of ventral marginal, with chisel-like distal extension forming spike. The clasper of G. atlantica is very similar to that of G. !urvescens. However, in G. atlantica the rhipidion is more proximally located; the sentinel is more sharply pointed (Fig. 3d); the dorsal terminal 3 is narrower along its proximal section where it articulates with the dorsal terminal 2; and the distal margin of accessory terminal 2 is more truncate (Fig. 4d, e, f). Unfortunately no adult males of P. fischeri were available for examination of claspers. Nellrocranium.-The neurocranium of G.jllrvescens has a relatively short, stout, tapering rostral shaft that fails to reach tip of snout (Fig. 5a); rostral appendices enlarged, anteriorly fused to rostral node, cylindrical, posteriorly straddling rostral shaft; propterygium of pectoral fin reaching tip of rostral node; nasal capsules large, set at a 35° angle to the transverse axis of the neurocranium and rhomboidal in shape with antorbital condyles located along posterior borders; with foramina of profundus nerve (foramina for ethmoid nerve of Hulley) located on dorsolateral aspect of nasal capsule; with anterior foramen for preorbital canal (foramen for ophthalmic nerve of Hulley) located dorsally at junction of nasal capsules and rostral base; roof of each nasal capsule with a basal fenestra extending posterolaterally from anterior foramen for preorbital canal to preorbital wall; internasal septum extremely narrow, with inner walls of nasal capsule bulging over and meeting along midline of neurocranium; interorbital region narrow; preorbital process merging with deeply incised supraorbital crest; postorbital process low and bifurcated distally; anterior fontanelle tear-shaped, not grooved anteriorly, separated from ovoid posterior fontanelle by a narrow epiphysial bridge; large cranial foramen for otic branch of facial nerve (superficial ophthalmic nerve of Hulley) located medial to postorbital process; posterior foramen for preorbital canal located on anterodorsal aspect of orbit (Fig. 6a); orbitonasal canal situated on anteroventral aspect of orbit; optic nerve foramen extremely large situated just anterior to midline of orbit; foramen for anterior cerebral vein anterior and slightly dorsal to optic nerve foramen, above orbitonasal canal; trochlear nerve foramen posterior and dorsal to optic nerve foramen; oculomotor nerve foramen situated above optic stalk; large orbital fissure (trigeminofacialis nerve foramen, prootic nerve foramen of Hulley) situated on posterior aspect of orbit, anterior to foramen for hyomandibular branch of facial nerve; foramen for interorbital McEACHRAN AND COMPAGNO: TAXONOMIC STUDIES OF RAJOIDEI 539

••• 540 BULLETINOFMARlNESCIENCE,VOL.29, NO.4, 1979

II os eS

lcm c

Figure 6. Lateral view of neurocranium. a. Gargesiella furvescens SOSC, ANTON BRUUN, Cr. 16 between Callao, Peru and Galapagos Islands; b. G. atlantica NMFS SL, Caribbean Sea; c. Pseudoraja fischeri NMFS SL, OREGONII, Sta. 11154; ac-anterior cerebral vein foramen, antc-antorbital condyle, es-efferent spiracular artery foramen, hf-hyomandibular facet, into-interorbital vein foramen, obf-otic branch of facial nerve foramen, of-orbital fissure, one-orbital nasal canal, os- optic stalk. poc-preorbital canal foramen, II-optic nerve foramen, III-oculomotor nerve foramen. IV-trochlear nerve foramen, VII-hyomandibular branch of facial nerve foramen.

vein situated between optic stalk and orbital fissure, dorsal to efferent spiracular artery foramen (afferent pseudobranchial artery of RuBey) which is located along ventral rim of orbit; hyomandibular facet located on mesial ventral aspect of otic capsule; jugal arches (postotic processes) lacking (Fig, 7a); vagus nerve foramen located lateral to occipital condyles; glossopharyngeal nerve foramen lateral to vagus nerve foramen; foramen for lateralis branch of vagus nerve dorsal to vagus nerve foramen; foramen for posterior cerebral vein situated lateral to upper rim McEACHRANAND COMPAGNO:TAXONOMICSTUDIES OF RAJOIDEI 541

,, ,I - - - .••.

end

/ / "- / , I " I \ \ I I \ /" -.. / '- .•.•.

C ... ". ,, " " , I " , ,, , jlcm ,, , , I I ,~ I , ". ".

Figure 7. Posterior view of neurocranium. a. GlIrgesiellafllrvescens SOSC, ANTON BRUUN, Cr. 16, between Callao, Peru and Galapagos Islands; b. G. at/antica N MFS SL, Caribbean Sea; c. Pseudoraja fisc/leri NMFS SL, OREGON 11, Sta. 11154; end-endolymphatic foramen, ja-jugal arch, IbX-lateralis branch of vagus nerve foramen, oc-occipital condyle. pc-posterior cerebral vein foramen, peri-perilymphatic foramen. IX-glossopharyngeal nerve foramen. X-vagus nerve foramen. 542 BULLETIN OF MARINE SCIENCE. VOL. 29, NO.4, 1979

c McEACHRAN AND COMPAGNO: TAXONOMIC STUDIES OF RAJOIDEI 543

Table 2. GIII"f:esiella fllrvescens. G. atlantica. and Pselldoraja fischeri cranial measurements and proportions, measurements in millimeters, proportions in percent of nasobasal length (measurement after Hubbs and Ishiyama (1968) except those marked *)

G. furvescens G. mlamica P. fisch.~rj 576 mm TL 9t 462 mm TL 9 375 mm TL 9 Callao. Peru Caribbean Gulf of Mexico

mm* %NB§ mm %NB mm %NB

Nasobasallength" 51 39 38 Cranial length 78 153 68 174 43+ Rostral cartilahe 27 53 29 74 5+ Prefontanelle length 28 55 30 77 1+ Cranial width 46 90 36 92 38 100 Interorbital width 13 25 10 26 10 26 Rostral base 3 6 2 5 5 13 Anterior fontanelle length 17 33 16 41 13 34 Anterior fontanelle width 4 8 4 10 5 II Posterior fontanelle length 18 35 12 31 15 38 Posterior fontanelle width 4 8 3 8 3 8 Rostral appendix length 24 47 22 56 Rostral appendix width 4 8 5 13 Rostral cleft length 14 27 14 35 Cranial height 10 20 9 23 II 29 Height of rostral cartilage 5 ]0 5 13 6 16 Width across otic capsules* 23 45 19 49 19 50 Least width of basal plate" 10 20 7 18 9 24 Greatest width of nasal aperture" 22 43 21 54 17 45 Internasal width* 4 8 3 8 4 II t Length estimated bCCHUSC tajl was damaged. ~ mm = linear measurement in millimeters. § NB = Nasobasallength. of foramen magnum; basal plate extremely narrow, especially at level of orbits (Fig. 8a); hyomandibula anterolaterally oriented and slender (Fig. 5a). The neurocranium of G, atlantica closely resembles that of G. furvescens except that the nasal capsules of the former species are more rounded, the anterior fontanelle is more constricted by the nasal capsules anteriorly and the rostral shaft is much more attenuated and elongated and nearly reaches the posterior junction of the rostral appendices and the rostral node (Fig. 5b, 6b, 7b, 8b, Table 2). Neurocranium of P. fischeri lacks a rostral shaft; rostral base extending barely anterior of anterior rim of nasal capsule (Fig. 5c); rostral node and rostral appendices fused into plate at tip of snout, with concave anterior margin, tapered posterolateral extensions and acute posteromedial border, and two foramina located on anterolateral aspect of node; propterygium of pectoral fin reaches rostral plate; nasal capsules set at about a 25° angle to transverse axis of neurocranium, with smoothly rounded outer corners, antorbital condyles situated on posterolateral aspect, with profundus nerve foramen near leading edge, and anterior foramen for preorbital canal located' along leading edge at junction of nasal capsules and rostral shaft; roof of each nasal capsule with a basal fenestra running 544 BULLETIN OF MARINE SCIENCE. VOL. 29. NO.4. 1979 scp ocp lcm lcm n.' ner 01 01 mlC ",Ie

prc pre

mH moe pvl pvl a lcm

odl.

ob, mlc

pre

ovl.

m>' pvl C

Figure 9. Lateral view ofscapulocoracoid. a. Gurgesiellafurvescens SOSe, ANTON BRUUN, Cr. 16, between Callao, Peru and Galapagos Islands; b. G. atlantica NMFS SL, Caribbean Sea; c. Pseudoraja fischeri NMFS SL, OREGON II, Sta. 11154; adfe-anterodorsal fenestra, af-anterior fenestra, avfe- anteroventral fenestra, msc-mesocondyle, mtc-metacondyle, ner-neopterygial ridge, pdfe-postdorsal fenestra, prc-procondyle, pvf-postventral foramina, scp-scapular process. diagonally from just behind anterior foramen for preorbital canal to preorbital wall; internasal septum narrow with medial walls of nasal capsules meeting along midline above nasal septum; interorbital region narrow; preorbital processes poorly developed, merging into deeply incised supraorbital crest; postorbital process well developed; anterior fontanelle tear-shaped, with rounded posterior margin, anteriorly extending to near tip of rostral base; posterior fontanelle constricted just past midlength and divided into two fontanelles; large cranial foramen for otic branch of facial nerve situated medial to postorbital process; jugal arches very slender; posterior foramen for pre orbital canal situated on anterodorsal aspect of orbit; orbitonasal canal situated on anteroventral aspect of orbit (Fig. 6c); optic nerve foramen located anterior to midline of orbit; foramen for anterior cerebral vein anterior and dorsal to optic nerve foramen, slightly posterior to orbitonasal canal; trochlear nerve foramen situated above optic nerve foramen; oculomotor nerve foramen above and slightly anterior to optic stalk; orbital fissure situated on posterior aspect of orbit, separated from more posterior hyomandibular branch of facial nerve foramen by prefacial commissure; interorbital vein foramen located between optic stalk and orbital fissure, above efferent spiracular artery foramen; hyomandibular facet situated on ventromesial aspect of otic capsule; vagus nerve foramen situated lateral to occipital condyle (Fig. 7c); glossopharyngeal nerve foramen ventral to jugal arch; foramen for lateralis branch of vagus nerve dorsal to vagus nerve foramen; foramen for posterior cerebral McEACHRAN AND COMPAGNO: TAXONOMIC STUDIES OF RAJOIDEI 545

prep

obI

Icm

Figure 10. Dorsal view of pelvic girdle. a. Gurgesiella furvescens SOSC, ANTON BRUUN, Cr. 16 between Callao, Peru and Galapagos Islands; b. G. atlantica NMFS SL, Caribbean Sea; c. Pseudoraja fischeri NMFS SL, OREGON II, Sta. 11154; ilp-itiac process, obt-obturator foramina, prep-prepelvic process.

vein on a vertical with and dorsal to vagus nerve foramen; basal plate extremely narrow especially at level of orbits (Fig. 8c). Hyomandibula inclined anteriorly and moderately slender (Fig. 5c). Pectoral Gird/e.-The lateral face of the pectoral girdle (scapulocoracoid) of G. jUr!'escens, like that of most rajoids examined to date, is anteroposteriorly elongated (Compagno, unpublished data). The anterior bridge is missing, anterior fenestra rather narrow, postdorsal fenestra slightly expanded anteroposteriorly, mesocondyle elongated, four postventral foramina, a neopterygial ridge connect- ing the meso and metacondyles, and a low scapular process (Fig. 9a). The scapulocoracoid of G. atlantica is similar to that of G. jurvescens except that the lateral face and the postdorsal fenestra are more expanded and there are only three postventral foramina (Fig. 9b, Table 3). In P. fischeri the lateral face of the scapulocoracoid is considerably shorter and taller, with a very slender anterior bridge dividing the anterodorsal and anteroventral fenestra, the postdorsal fenes- 546 BULLETIN OF MARINE SCIENCE, VOL. 29, NO.4, 1979

Table 3. Gurgesiella furvescens, G. atlantica and Pseudoraja fischeri seapuloeoraeoid measurements and proportions (Measurements in millimeters and proportions in percent of greatest length)

G. furvescens G. atLantica P. fischl'ri 576 mm TL ~t 462 mm TL 2 375 mm TL ~ Callao. Peru Caribbean Gulf of Mexico

mmt %GL§ mm %GL mm %GL

Greatest length 31 28 18 Greatest height 21 68 15 54 17 94 Premesoeondyle 13 42 12 43 8 44 Postmesocondyle 18 58 16 57 10 56 Postdorsal fenestra length 9 29 10 36 5 28 Postdorsal fenestra height 9 29 5 18 2 II Anterior fenestra length 7 23 8 29 2 II Anterior fenestra height 13 42 9 32 4 22 Height of rear corner 16 52 II 39 9 50 t Lenglh eSlimated because lail was damaged. ~ mm = linear measurement in millimeters. § GL = Greatest length. tra is elongate but irregular in outline, without a neopterygial ridge, with three postventral foramina, and the mesocondyle is not expanded (Fig. 9c, Table 3). Pelvic Girdle.-The pelvic girdle of G. furvescens consists of an arched puboischiadic bar with very poorly developed prepelvic processes (Fig. lOa). The iliac processes are moderately recurved and directed medially. The iliac region possesses one obturator foramen. The anterior condyle for the pelvic radials is rather slender. The pelvic girdle of G. atlantica is very similar to that of G. furvescens except that the iliac processes are less recurved and directed medially (Fig. lOb). The pelvic girdle of P.fischeri is straight along its anterior margin and possesses moderately developed prepelvic processes and strongly recurved iliac processes. The iliac region has one obturator foramen and the anterior condyle for the pelvic radials is more massive than in Gurgesiella (Fig. IOc).

DISCUSSION Gurgesiella furvescens and G. atlantica are very similar to each other in char- actersjudged to be of high taxonomic value in rajoids (lshiyama, 1958; Stehmann, 1970; Rulley, 1972a) and are more similar to each other in these characters than either is to Pseudoraja fischeri, strongly supporting Hulley's (1972b) removal of G. atlantica from Pseudoraja. Our progress in understanding the phylogenetic realtionship of Gurgesiella and Pseudoraja and their interrelationships with other rajoids is hampered by the failure of previous studies on rajoids to clearly analyze the polarity of character states used in relating taxa, lack of knowledge of many taxa and the taxonomic diversity of Rajoidei. Genera and subgenera have been based on common possession of various characters (Stehmann, 1970; Hulley, 1972a, ]973), but whether the common states were shared derived ones indicating common descent from immediate ancestors shared by no other taxa, derived states resulting from parallel evolution, or shared primitive ones has generally not been specified. In seeking to elucidate the relation of Gurgesiella and Pselldoraja we now propose hypotheses that we regard as most probable: (I) Gurgesiella and Pselldoraja are not sister genera, and specific resemblances between them are due to their sharing primitive (synplesiomorphic) characters. (2) Gllrgesiella and Pselldoraja are not sister genera, and specific resemblances between them are the result of parallel- McEACHRAN AND COMPAGNO: TAXONOMIC STUDIES OF RAJOIDEI 547 ism. (3) Gurgesie/la and Pseudoraja are sister genera forming a natural monophyletic group of uncertain family group rank. A number of the character states shared by GurgesieLla and Pseudoraja, when compared with those of other rajoids and primative batoids i.e. rhinobatoids and pristoids, are, within Rajoidei, considered to be derived. Thus possession of these negates the first hypothesis: (1) Internasal septum extremely narrow, with inner walls of nasal capsules bulging medial/y over it to meet each other medially. (2) Basal plate extremely narrow, especially at orbits. (3) Anterior lobes of pelvic fins greatly expanded laterally, with posterior margins more or less straight. (4) Jugal arches very slender or absent. (5) Nostrils greatly elongated anteroposteriorly, distance between the posterior corner of the mouth and the anterior end of the incurrent aperture of the nostril on each side about equal to the internasal space. (6) Roof of each nasal capsule with a basal fenestra. (7) Presence of a rostral process. (8) Loss of both dorsal fins. (9) Caudal fin without terminal lobe. (10) Nasal capsules greatly expanded anterolateral/y. (II) Supraorbital crests deeply incised medially. At least five of the above character states are unique to Gurgesiella and Pseu- doraja and thus support hypothesis three (that GurgesieLla and Pseudoraja form a monophyletic group). The remainder of the character states are shared with other rajoid taxa and cannot be used alone in determining the relationship of the two genera. However, the character states which are shared with other taxa do not falsify a direct relationship between the two genera and may serve to relate them to other taxa. In sequence: (1) The extreme narrowness of the internasal septum and dorsal contact of the nasal capsules are, as far as is known, unique for GurgesieLla and Pseudoraja. (2) The narrowing of the basal plate is more extreme than in any other known rajoid or batoid. (3) Sympterygia, several species of Psammobatis and the Raja pulehra-R. binoeulata subgroup in Raja (Diptllrlls) have pelvic fins with posterior margins that are more or less straight and not deeply incised as in most rajoids, but none of these taxa have the pelvic fins greatly expanded laterally as in Pseudoraja and Gurgesiella. (4) All other known rajoids have rather stout jugal arches, hence reduction of the jugal arches in Pseudoraja may be a derived intermediate step related to their subsequent loss in Gllrgesiella, as they are slenderer in the former genus than in other rajoids. (5) The narial region is more anteroposteriorly elongated in Pseudoraja and Gur- gesiella than most other rajoids (which have the distance between mouth corners and incurrent apertures mostly Y2to ~ of the internaral space), although some species of Breviraja, Psammobatis and Raja (Atlantoraja) have similarly elongated narial regions. (6) The dorsal fenestrae of the nasal capsules are also found in 'R{~ja' nitida and several species of Psammobatis. (7) Rostral processes occur also in Anaeanthobatis, Psammobatis and 'Raja' nitida. (8) One dorsal fin is absent in Arhynehobatis, and both are absent in Anaeanthobatis. (9) The terminal lobe of the caudal fin is lacking in Anaeanthobatis and Arhynehobatis. (10) Bre- viraja. Raja (Malaeoraja) spina cidermis , and also to a lesser extent a few other deepwater Raja species have enlarged, diagonally expanded nasal capsules (Hul- ley, 1972a; Hulley and Stehmann, 1977). (II) The supraorbital crest is also incised in a number of rajoids (lshiyama, 1958, fig. 27N, P; Stehmann, 1970, pI. 21,23, 24; Hulley, 1972a, fig. 49, 52-54). The scapulocoracoid and rostral differences in the two genera suggest the Gur- gesiella and Pseudoraja do not form a monophyletic group but are more closely related to other rajoids than they are to each other (second hypothesis). The scapulocoracoid has not hitherto been utilized in rajoid phylogenetic studies. However, we have examined its morphology in about 100 species of rajoids and 548 BULLETIN OF MARINE SCIENCE, VOL. 29, NO.4, 1979 are impressed with its range of variation, especially in the morphology of its lateral face. The scapulocoracoid of rajoids, and other batoids, will be discussed in detail elsewhere (Compagno and McEachran, in prep.), but a few remarks on the phylogeny of certain rajoid scapulocoracoid types are in order here. In primitive living batoids (rhinobatoids and pristoids) the scapulocoracoid is very high and short, as in sharks, with the three articular condyles for the pectoral basals not enlarged, close together in a horizontal line and about equidistant on the lateral face. Four small neurovascular foramina are usually present, a pair above and below the interspaces between the three condyles. Rajoid scapulocoracoid types that most closely approximate this primitive type are found in some species of Breviraja and Psammobatis, and in the Raja subgenera Amblyraja. Leucoraja and Rajella. Gurgesiella has a derived type especially similar to that in Anacan- thobatis and Cruriraja (both of which lack an anterior bridge dividing the anterior fenestra as in Gurgesiella), but also to that in Raja (Rioraja and At/af/toraja) which have the anterior bridge. In all of these forms the lateral face of the scapulocoracoid is low and elongated, the anterior foramen (or paired anterodorsal and anteroventral foramina, where an anterior bridge is present) expanded as fenestrae, the postdorsal foramen more or less expanded as a fenestra, and the postventral foramen multiple. The scapulocoracoid of Gurgesiella differs from that of the other genera and the subgenera mentioned by being shorter, higher and in having a smaller postdorsal fenestra and fewer postventral foramina. The scapulocoracoid of Pseudoraja is less elongated anteroposteriorly, higher, and possesses a shorter and smaller postdorsal fenestra, a higher scapular process and a very narrow anterior bridge. The Pseudoraja scapulocoracoid is more similar to that of several Psammobatis species than to that of Gurgesiella, but is intermediate between these genera in having a reduced anterior bridge, larger anterodorsal and anteroventral fenestrae than in Psammobatis, but a shorter postdorsal fenestrae than in Gurgesiella. However, similarities between the scap- ulocoracoids of Psammobatis and Pseudoraja are primitive ones that do not preclude the derivation of the scapulocoracoid type of Gurgesiella from that of Pseudoraja. The rostra of both Gurgesiella and Pseudoraja are reduced, as in various other rajoids, but in different ways from each other and from other rajoids. That of Pseudoraja lacks a rostral shaft (unique for rajoids) and has a low rostral base unconnected to the bilobate rostral node. In Gurgesiella the rostral shaft is relatively stout, tapering, and elongated anteriorly, but ends in a slender or blunt tip just posterior to the rostral node without being connected with it. The rostral appendices of Gurgesiella are unique, elongated, cylindrical rods that are greatly elongated posteriorly and closely flank the rostral shaft, while those of Pselldoraja are short, flat, posterolaterally expanded wings much like those in Breviraja, Bathyraja, Rhinoraja, Psammobatis, Sympterygia and Arhynchobatis. The rostral type in Gurgesiella is a derived type with primitive features (particularly the stout, tapering rostral shaft) that suggests that it did not evolve from the more reduced types in Pseudoraja and other rajoids but evolved from a type with an unreduced or partially reduced rostrum (which could also have given rise to the reduced type in Pseudoraja). The rostral shaft of Pseudoraja is so greatly reduced that it is difficult to determine if the arrangement in this genus was evolved from a distally jointed or incomplete tapering shaft as in Gllrgesiella, or from a proximally jointed, slender, band-like shaft as in Arhynchobatis (Garrick, 1954), Rhi- /loraja (Ishiyama, 1958, 1967), Psammobatis and Sympterygia (Compagno and McEachran, unpubl. data). At least one species of Psammobatis (P. cf. extenta) and 'Raja' nitida have the rostral shaft posteriorly reduced so that there is a wide McEACHRAN AND COMPAGNO: TAXONOMIC STUDIES OF RAJOIDEI 549 gap between the rostral base and the posterior end of the shaft. Thus the condition in Pseudoraja could have been derived from the condition in Psammobatis, or from that of Gurgesiella by further reduction of the shaft. Claspers cannot be used at present to determine if Pseudoraja and Gurgesiella are related because no adult males of P. fischeri are available. The claspers of GurgesieLla resemble those of Cruriraja and Anacanthobatis (as described by Rulley, 1972a, 1973) in having small rhipidia, dorsal marginal cartilages with a distal extension, no direct connection between the dorsal terminal cartilages (DT2, DTa) and the axial cartilage, and poorly differentiated ventral terminal cartilages. The clasper of Gurgesiella especially resembles that of Anacanthobatis borneensis, which lacks dorsal terminal I and 4 cartilages and has similarly shaped dorsal terminal 2, ventral terminal, accessory terminal I, and accessory terminal 2 cartilages (Rulley, 1973, figs. II, 12). Unlike Gurgesiella, A. borneensis lacks a distal extension or projection on the dorsal marginal, the dorsal terminal 3 is not joined to the dorsal marginal, the anterior notch on the ventral terminal is proximally located, the accessory terminal I lacks a long proximal arm (which in GurgesieLla forms part of the margin of the ventral lobe of the glans) and accessory terminal 2 possesses an attachment process joining the axial cartilage (Rul- ley, 1973). The significance of the clasper similarities between Gurgesiella and Anacan- t/zobatis is unclear, especially because of considerable variation in the claspers of different Anacant/Zobatis species, the preliminary nature of our understanding of the phylogeny of clasper structures, and absence of information on the claspers of Pseudoraja. The close resemblance of the claspers of A. borneensis to those of GurgesieLla may be due to convergence, as A. borneensis possesses shared derived characters with other members of its genus which Gurgesiella lacks, and seems to be derived in clasper characters relative to other species of Anacan- t/zobatis (data from Rulley, 1972a, 1973). Hulley (1972a, 1973) placed great phylogenetic weight on possession of a rhipidion, using this character to divide Rajoidei into a derived group with a rhipidion (Anacanthobatis, CruriraJa, BreviraJa and Raja subgenera Dipturus, AmblyraJa, Malacoraja, Leucoraja and RajeUa as well as GurgesieUa) and a primitive one which lacks it (Bathyraja, Raja and Rostroraja). However, other characters (especially the scapulocoracoid) suggest that secondary loss of the rhipidion is in- volved in a few groups (most likely in the subgenera Raja and Rostroraja). At the present time we are uncertain if the 'rhipidion' (not homologous to the true rhipidion of certain sharks) is a primitive feature of rajoid claspers or a derived character within the rajoids. The rajoid group lacking a rhipidion possesses a distal extension of the dorsal marginal cartilage which forms the clasper component pseudorhipidion, generally has a poorly differentiated ventral terminal (in Bat/zyraja and Raja) and lacks a direct connection of the dorsal terminals and axial cartilage (in Bathyraja and Raja). However, Gurgesiella possesses a distal extension of the dorsal marginal (as do many species of the Raja subgenus Dip- tU1'llS although not hitherto reported), a moderately differentiated ventral terminal and lacks a direct connection of the dorsal terminals and the axial. Gurgesiella possesses characters found in both of RuBey's basal groups of Rajoidei, thus negating the use of the clasper structure as it is currently interpreted in relating Gurgesiella with other rajoid taxa. Several characters in which GurgesieLla and Pseudoraja differ are apparently of little use in determining the phyletic relationships of these genera. The presence of oronasal pits in Pseudoraja (Bigelow and Schroeder, 1954) is not a unique character because it also occurs in a number of morphologically diverse and 550 BULLETIN OF MARINE SCIENCE, VOL. 29, NO.4, 1979 possibly distantly related skates, e.g. 'Raja' waitei, Raja subgenera Atlantoraja and Rioraja, and several species of Breviraja (McEachran and Compagno, un- pub\. data), and thus may have been independently derived in Pseudoraja. The pelvic girdle (puboischiadic bar) differs in the two genera, that of Gurge- siella being anteroposteriorly very narrow, transversely very wide and moderately arched anteriorly; while that of Pseudoraja is anteroposteriorly broad, transversely narrow and nearly straight (Hulley, 1972b). However, because of the considerable, almost random variation of pelvic girdle structures in rajoids (Hulley, 1972a, figs. 3, 4), lack of information on the pelvic girdles of many species, and hardly any derived points of special agreement between either Pseu- doraja or Gurgesiella and other genera and species, the pelvic girdle is not especially useful in determining the affinities of these species. The above character analysis indicates that the third hypothesis (that Gurge- siella and Pseudoraja form a monophyletic group) is the most parsimonious and thus the preferred hypothesis. The two genera share more unique derived characters with each other than either does with any other taxon. Greatly reduced internasal septum and medially expanded nasal capsules, extremely narrow basal plates, laterally expanded pelvic fins, reduced (or missing) jugal arches and elongated narial region are unique to Gurgesiella and Pseudoraja. Acceptance of the second hypothesis would necessitate the independent development of these character states. Character states for which Gurgesiella more closely resembles other taxa than Pseudoraja i.e. scapulocoracoid structure, and character states for which Pseudoraja more closely resembles other taxa than Gurgesiella i.e. scapulocoracoid structure and presence of an oronasal pit, appear to be due to secondary relationships and convergences. The scapulocoracoid of Pseudoraja is more derived than that of Psammobatis and related to the latter by possession of primitive character states. The scapulocoracoid of Gurgesiella is more derived than that of Pseudoraja and similar although less derived than those of Anacan- thobatis, Cruriraja, Raja (Rioraja) and R. (Atlantoraja). Thus the scapulocoracoid of Gurgesiella could have been derived from that of Pseudoraja. Rostral differences in the two genera do not negate a direct relationship but do indicate considerable evolution in this character in Pseudoraja since their vicariance. Although Hulley (1972b) pointed out several important differences (and several minor ones) between these genera (to which we have been able to add several more), still their similarities are compelling enough to regard them as sister groups comprising a monophyletic family-group taxon (regardless of rank). We feel that separate families for Pseudoraja and Gurgesiella are unwarranted and as a min- imal step merge Gurgesiellidae with Pseudorajidae. We tentatively retain Pseu- dorajidae as a distinct family with the reservation that determination of its final rank awaits critical evaluation of other rajoid families and the interrelationships of their component taxa. Phenetically Pseudoraja and Gurgesiella are closest to Psammobatis (Rajidae) and may be related to this genus as well as to Cruriraja and Anacanthobatis, but details of this are a matter for future exploration. As an interim treatment we present a definition of Pseudorajidae and its genera as follows:

Family Pseudorajidae Bigelow and Schroeder, 1954 = Family Gurgesiellidae de Buen, 1959 Rajoids with no dorsal fins (one dorsal occasionally present); no terminal lobe on caudal fin; tail extremely elongated, its length to cloaca about 1.5-2.0 times body length from cloaca to snout tip; anterior lobes of pelvic fins greatly ex- McEACHRAN AND COMPAGNO: TAXONOMIC STUDIES OF RAJOIDEI 551 panded, not isolated from posterior lobes as a separate pair of "limbs" but joined to it by nearly straight (not deeply incised) posterior margins of the fins; front of snout bluntly rounded, with a terminal process; nostrils greatly elongated, distance from incurrent aperture of nostril to mouth corner about equal to distance between nostrils; dorsal surface of body and pectoral rough with denticles; rostrum reduced, either with a space between the rostral shaft and node or with the shaft absent; nasal capsules greatly expanded, oval, and diagonal to basal plate, with longitudinally or diagonally fenestrated roofs; internasal septum very narrow, with nasal capsules abutting medially over it and crowding the precerebral fossa; basal plate of cranium very narrow; lateral face of scapulocoracoid anteroposteriorly elongated, with a small to large postdorsal fenestra, a large anterior fenestra (or anterodorsal and anteroventral fenestrae separated by a slender anterior bridge), and 3-4 postventral foramina; puboischiadic bar without greatly elongated prepelvic processes. Pseudoraja Bigelow and Schroeder, 1954 Pseudorajids with large thorns on dorsal surface of disc, including three large prescapulars, a mediscapular, and smaller lumbars at the midline of the back, a pair of scapulars on either side, and heavy orbital thorns; dorsal surface of disc with minute denticles, these close-set and with very long, slender cusps, giving the skin a velvety texture; rostral filament slender; a deep oronasal pit present; pores on underside of head dark-pigmented; lateral corners of disc broadly rounded; tips of anterior lobes of pelvic fins broadly rounded, posterior margin of fin very elastic and fanlike; tail rather short, about 1.5 times length of body; dorsal surface of disc spotted, tail banded; rostral node short and broad, with flat, broad rostral appendices, not cylindrical and not close to the midline; rostral shaft absent, a considerable space between rostral node and broad, low projection of rostral base; nasal capsules relatively small, transversely situated on cranium; jaws and hyomandibula relatively thick; scapulocoracoid relatively short and high, with prominent scapular process, a slender anterior bridge, and small postdorsal fenestra; puboischiadic bar anteroposteriorly broad but transversely narrow, not slender and anteriorly arched. SPECIES:Pseudoraja fischeri Bigelow and Schroeder, 1954. Gurgesiella de Buen, 1959 Pseudorajids without large thorns on midback, without scapulars or orbital thorns; minute denticles of dorsal surface of disc sparse, with low short cusps, skin not velvety; rostral process broad and thick; no oronasal pit; pores on underside of head light, not dark-pigmented; lateral corners of disc angular; tips of anterior lobes of pelvic fins bluntly pointed and narrow, posterior margin of fin not greatly elastic, expansile and fanlike; tail long, about twice the body length; dorsal sUlface plain, tail unbanded; clasper very long and slender, without dermal denticles and pseudosiphon, with pseudorhipidion, rhipidion and sharp-edged shield, dorsal marginal with distal extension, without dorsal terminal I, dorsal terminal 2 comma-shaped, dorsal terminal 3 with crenate distal margin not directly connected to axial, ventral terminal twisted laterally along its longitudinal axis, accessory terminal 1 and 2 rod-shaped and distally sharp-edged; rostral node elongated and narrow, with cylindrical rostral appendices that extend far posterior along the midline and flank the rostral shaft; rostral shaft present, variably elongated, with a stout base and tapering tip that ends behind the fork of the rostral appendices; nasal capsules relatively large and diagonally situated; jaws and hyo- 552 BULLETINOFMARINESCIENCE,VOL.29, NO.4, 1979

mandibula relatively slender; scapulocoracoid relatively long and low, with low scapular process, no anterior bridge, and relatively large postdorsal fenestrae, puboischiadic bar anteroposteriorly narrow but transversely broad, slender and anteriorly arched. SPECIES:Gurgesiella furvescens de Buen, 1959 and G. atlantica (Bigelow and Schroeder, ]962).

Materials Examined.-GlIrgesielia fllrvescens: SOSC (I) 32°I7'S, 71°39.5'W, ANTON BRUUN, Cr. 18A, LWK 66-44; SOSC (I) 32°08'S, 71°43'W, ANTON BRUUN, Cr. 18A, LWK 66-47; USNM acc. no. 266608 (6) 17-18 km NW Valparaiso, Chile; USNM acc. no. 266609 (2) off Valparaiso, Chile; SOSC (2) 07°49'S, 80038'W, ANTON BRUUN, Cr. 18B Sta. 754; SOSC (I) between Callao, Peru and Gahipagos Islands, ANTON BRUUN, Cr. 16; SU 40863 (I) 01033'S, 89°34.5'W.

GlIrgesielia atlantica: USNM 196444 (I) HOLOTYPE13°20'N, 82°02'W; USNM (uncat.) (I) 07"44'N, 53°49'W, OREGONII 10807; USNM (uncat.) (3) 07°48'N, 54°25'W, OREGONII 10603; USNM 278057 (I) 08°06'N, 57°41'W; NMFS SL 10260 (I) 11003'N, 7S018'W; USNM 289062; Ilo12'N, 74°21'W; USNM 278057 (I) 11026'N, 74°14'W; NMFS SL 12°IO'N, 72°52'W, OREGONII Sta. 11286; USNM 278057 (I) IZ044'N, 82°16'W; NMFS SL (5) 12°52'N, 70043'W, OREGONII Sta. 11299; USNM 278057 (4) 14°24'N, 81°48'W; NMFS SL (I) OREGONH Caribbean Sea. Pseudoraja fischeri: USNM 163368 (I) HOLOTYPE22°44'N, 86°41'W; MCZ 38175 (I) PARATYPE 22°41'N, 86°4I'W; MCZ 52241 (3) 15°38'N, 61°I5'W; USNM (uncat.) IS040'N, 61°09'W, OREGONII Sta. 10827; MCZ 41851 16°35'N, 8001O'W; USNM 148272 20019'N, 87°03.5'W; NMFS SL (I) 17°15'N, 62°22'W, OREGONII Sta. 10842; NMFS SL (I) 24°19.2'N, 87°40'W, OREGONII Sta. 11154.

ACKNOWLEDGMENTS

We would like to express our thanks to L. W. Knapp of the Oceanographic Sorting Center of the Smithsonian Institution and D. M. Cohen of the Systematics Laboratory of the National Marine Fisheries Service for providing us with specimens. We are grateful to the following curators for providing work space at their institutions and for loaning specimens needed for this study: W. N. ESl'hmeyer, K. F. Liem and S. H. Weitzman. We are especially appreciative of the encouragement and aid that C. L. Hubbs gave us in this study. He made all of his correspondence and unpublished data on skates, including photographs and radiographs of the Galapagos Islands specimen of G. furve.\'Cens available to us. Figures 3 through 7, 9, and 10 were prepared by D. Allen and Figure 8 was prepared by N. Tewell. This study was supported in part by the National Science Foundation Grant No. DEB78-11217.

LITERA TURE CITED

Bigelow, H. B., and W. C. Schroeder. 1953. Fishes of the western North Atlantic, Part 2. Sawfishes, guitarfishes, skates, rays, chimaeroids. Mem. Sears Fd. Mar. Res. (I): 588 pp. --. 1954. A new family, a new genus, and two new species of batoid fishes from the Gulf of Mexico. Breviora Mus. Compo Zoo!., Harvard Univ. (24): 1-16. --. 1962. New and little known batoid fishes from the Western Atlantic. Bull. Mus. Compo Zool., Harvard Univ. 128: 162-244. --. 1965. A further account of batoid fishes from the Western Atlantic. Bull. Mus. Compo Zoo!., Harvard Univ. 132: 446-477. Compagno, L. J. V. 1973. Interrelationships of living elasmobranchs. Pages 15-61 in P. H. Green- wood, R. S. Miles, and C. Patterson, eds. Interrelationships of fishes. Academic Press. Daniel, J. F. 1934. The elasmobranch fishes. University of California Press. 332 pp. de Buen, F. 1959. Notas preliminares sobre la fauna marina preabismal de Chile, con descripcion de una familia de rayas, dos generos y siete especies nuevos. Bol. Mus. Nac. Hist. Nat. 27: 173- 201. Garrack, J. A. F. 1954. Studies on New Zealand Elasmobranchii. Part I. Two further specimens of Arhynchobatis asperrimus Waite (Batoidei), with an account of the skeleton and a discussion on the systematic position of the species. Trans. Royal Soc. New Zealand 82: 119-132. Hubbs, C. L., and R. Ishiyama. 1968. Methods for the taxonomic study and description of skates (Rajidae). Copeia 1968: 483-49\. Hulley, P. A. I972a. The origin, interrelationships and distribution of southern African Rajidae (Chondrichthyes, Batoidei). Ann. S. Afr. Mus. 60: 1-103. McEACHRANAND CaMPAGNa: TAXONOMICSTUDIES OF RAJOIDEI 553

---. I972b. The family Gurgesiellidae (Chondrichthyes, Batoidei) with references to Pseudoraja atlantica Bigelow and Schroeder. Copeia 1972: 356-359. --. 1973. Interrelationships within the Anacanthobatidae (Chondrichthyes, Rajoidea), with a description of the lectotype of Anacanthobatis marmoratus Von Bonde and Swart, 1923. Ann. S. Afr. Mus. 62: 131-158. ---, and M. Stehmann. 1977. The validity of Malacoraja Stehmann, 1970 (Chondrichthyes, Batoidei, Rajidae) and its phylogenetic significance. Ann. S. Afr. Mus. 72: 227-237. Ishiyama, R. 1958. Studies on the rajid fishes (Rajidae) found in the waters around Japan. J. Shi- monoseki Coil. Fish. 7: 1-394. --. 1967. Fauna Japonica, Rajidae (pisces). Tokyo Electrical Engineering College Press, Tokyo, Japan. 84 pp. Krefft, G. 1968. Knorpelfische (Chondrichthyes) aus dem tropischen Ostatlantik. Atlantide Rep. (10): 33-76. Stehmann, M. 1970. Vergleichend morphologische und anatomische Untersuchungen zur Neuord- nung der Systematik der nordostatlantischen Rajidae. Arch. Fisch. Wiss. 21: 73-164. Stehmann, M. 1976. Revision der Rajoiden-Arten des nordlichen Indischen Ozean und Indopazifik (Elasmobranchii, Batoidea, Rajiformes). Beaufortia 24: 133-175.

DATE ACCEPTED: September ]4, 1978.

ADDRESSES: (J.D.M.) Department of Wildlife and Fisheries Sciences, Texas A&M University, Col- lege Station, TX 77843 and (L.l. V.c.) Division of Systematic Biology, SUI/({ord University, Stw(f(Jrd, California 94305.