Short Description
Original Description of the holotype after BULLIS & CARPENTER, 1966 [3658]: Body about as high at dorsal spine as at second dorsal origin; moderately compressed and tapering pos-teriorly into long caudal filament; more than half as thick as high at pectoral and pelvic origin; height at dorsal spine about half preorbital length. Snout extends along a plane below eye level and turns slightly downward at tip; width directly in front of mouth about one-fifth greater than orbit length, this width maintained anteriorly about one-fourth of distance from orbit to snout tip and from there evenly tapering to sharp point. Preorbital length one-third distance between snout tip and end of anal fin base. Head length about half the length from snout tip to anal fin origin; width behind eyes about three-fourths body height at dorsal spine. Horizontal diameter of orbit about one-fifth preorbital length. Mouth width about four-fifths orbit length. Inter-nasal width about one-third orbit length. Dorsal spine triangular in cross section, with a row of serrations along each of its two posterior edges; situated directly over anterior pectoral insertion; about half as long as distance from snout tip to posterior margin of eye; upper two-thirds free from fin. First dorsal fin triangular with acute apex; posterior margin nearly straight; multiple ceratotrichia rays partly recessed into a groove that extends about half the interspace between dorsals; when folded extends slightly posterior to second dorsal origin. Interspace between dorsals about half orbit length. Sec-ond dorsal reaches maximum height slightly anterior to pectoral tip (when these are adpressed to body), then decreases posteriorly and ends abruptly above anterior insertion of anal fin; maximum height less than orbit length; slightly less than preorbital length; separated from upper caudal origin by inter-space slightly more than half orbit length. Caudal fin tapers to long slender bandlike filament; epiural origin indistinct; maximum height of epiural about one-eighth orbit length; length about three times that of first dorsal. Hypural originates slightly pos-terior to epiural origin and extends posterior to epiural termination. Maximum height about five times that of epiural and about four-fifths body height at end of second dorsal fin. Anal fin elongate, pointed; tip extending behind hypural origin; base about four-fifths orbit length. Pelvic fins rounded on inner margin; slightly pointed; when adpressed to body their tips reach about three-fourths posteriorly along second dorsal fin. Pectorals large and subtriangular; inner margins broadly rounded; tips strongly pointed; about as long as preorbital length; tips when adpressed to body reach about three-fourths distance along anterior outer pelvic margins. Mucous canals in form of narrow slits. From occipital canal and orbital canal con-fluence (about halfway between dorsal spine origin and posterior margin of eye), lateral canal extends posteriorly in an irregular wavy line to a point one-fourth posteriorly along hypural, then descends at a 45? angle and extends along lower margin of caudal axis to tip of caudal filament. Jugular canal and oral canals, with a short interspace about one-sixth to one-seventh orbit length be-tween them, arise jointly from orbital canal. Angular (maxillary) canal joins oral canal on side of head directly beneath middle of eye; extends anteriorly on ventral surface of snout at slight oblique angle to form blunt angular canal loop with median sym-metrical bilobate notch; notch located slightly less than half distance from anterior margin of eye to snout tip. Suborbital canal extends anteriorly with a short curve in front of eye, follows lateral snout edge, then turns downward (to ventral side of snout) at an acute angle to form a branch. One arm of branch extends anteriorly to snout tip; the other runs posteriorly on ventral side of snout (just off lateral axis) to half length of angular canal loop; turns inward toward midventral line, but terminates abruptly before reaching loop of angular canal, with an interspace of 10-15% the eye length be-tween the two. Junction of cranial canal with aural canal an acute 45? angle. Aural extends inward to middorsal line where a posteriorly directed apex is formed. Cranial canal (with dorsolateral branches between eyes) is broad at aural junction but tapers anteriorly to constriction near anterior mar-gin of orbit, then becomes more separate and extends on relatively straight line to snout tip (Fig. 3). Ventral surface of snout with numerous minute mucous pores, especi-ally in area of angular canal loop. Large pores (six or seven) are located near junc-tion of occipital lateral, and orbital canals; a few strung out over eye, with many found on top of head near anterior margin of orbit. Dental plates with ridges and knobs. Vomerine (anterior upper) plates each with five beaded radial ridges. Palatine (posterior upper) plates subtriangular, about twice as long as vomerines, each with deep median groove extending entire length; anterior inner margin of groove with single or double series of knobs closely arranged; laterally from these and extending posteriorly from junction of vomerine and palatine plates is another row of five or six knobs. Anterior outer part of palatine plate with single row of seven knobs; directly behind and con-tinuous with these a row of smaller knobs extends for short distance on outer margin; lateral to median groove is elevated or swollen area with a series of five to six knobs; elevated area slopes posteriorly and laterally to flat plane. Lower (mandibular) plates about as long as palatines; about one and one-half times wide as long; anterior margin irregular; knobs, located in two rows on each plate, are close together and appear as series of teeth. One row, located just anterior to swollen part, extends forward to free edge; the other, located on outer margin, extends posteriorly to about half distance of swollen area. Deep median longitudinal groove, beginning pos-terior to radial ridges, extends entire length of plates, flares out and deepens on posterior extremity; bordered laterally by swollen areas of plates; width on posterior end about half that of plates. Low median ridge ex-tends length of plates in groove where plates connect. Tongue, located in longitudinal groove of dental plates, has numerous fleshy nodules and small papillae of various sizes. Color in preservative (50% isopropanol) is an even dark brown with blackish fins.

Distribution
Western Central Atlantic: Caribbean Sea off the coasts of Colombia and Venezuela.
first record: 2017: Caribbean of Guatemala [25054]; Source: www.gbif.org

Biology
Oviparous [17086].

Size / Weight / Age
59.6 cm TL (male/unsexed; [3658]); 74.5 cm TL (female)

Habitat
bathydemersal; marine; depth range 340 - 600 m [3585]

Remarks
shark-references Species-ID=4101;