Tofino Basin cone teeth
(Figure 65) are triangular-shaped and without a cutting edge (occlusal crest). Some important characteristics are tooth curvature, margins, inline type and size, presence of striations, outline ornamentation, apex acuteness and shadow, and the nature of the transverse line.
Undescribed cone teeth (13 new subtypes) were too rare to designate a name and full description. The utilitarian code and a brief description in "Remarks" are provided. Another 8 distinct specimens were opaque, difficult to illustrate, and not described. An additional 9 specimens were fragments and could not be identified.
List of identified cone teeth:
cf. triangle with parallel inline Doyle et al. 1974
cf. small triangle long striations Dunsworth et al. 1975
cf. striated triangle Ramsey et al. 1976
cf. curved triangle, parallel-sided inline new subtype
small pointed triangle Tway et al. 1985
cf. curved triangle wide inline new subtype
curved triangle wide inline new subtype
narrow tall triangle, cone inline new subtype
narrow tall triangle, inflated inline apex new subtype
narrow tall triangle, irregular threaded inline new subtype
shadowed high inline cone new subtype cf. long triangle stepped margin Doyle et al. 1974 and cf. angled cone and bulbous base new subtype
shadowed curved blunt triangle new subtype
dome-top triangle bowed inline new subtype
curved triangle, striated inline new subtype
cf. curved flared triangle Ramsey et al. 1976
curved triangle, parallel-sided inline new subtype
cf. narrow curved triangle Doyle et al. 1974
cf. short triangle stepped margin Doyle et al. 1974
cf. long triangle stepped margin Doyle et al. 1974
angled cone and bulbous base new subtype
cf. triangle small top Ramsey et al. 1976
cf. triangular triangle Kozarek and Orr 1980
Undescribed cone teeth (13 subtypes):
undescribed cone teeth, Form A
undescribed cone teeth, Form B
undescribed cone teeth, Form C
undescribed cone teeth, Form D
undescribed cone teeth, Form E
undescribed cone teeth, Form F
undescribed cone teeth, Form G
undescribed cone teeth, Form H
undescribed cone teeth, Form I
undescribed cone teeth, Form J
undescribed cone teeth, Form K
undescribed cone teeth, Form L
undescribed cone teeth, Form M
cf. triangle with parallel inline
Doyle et al. 1974, p. 846
Figure 66
a9/b1/c1/d1/e1/f4a+b/g3+8/h1,2,5/i2,3/j2,3/k7/m0/n~2/p0/q10/r1/s3/t2/z0
Characters: Tooth triangular and cone-shaped; with no occlusal crest ridge or flange; circular in cross-section; with thin tubular parallel sided inline that extends from base to beyond centre height of tooth but not to apex; inline hollow as seen at tooth base; with apical and lateral shadows; both margins straight to slightly convex; base breaks irregularly creating margins of different lengths; apex blunt; taller than wide (ratio ~2:1); outer surface pitted and with slightly raised short striations.
Remarks: This specimen differs from triangle with parallel inline by having 1) an inline apex well above the crown halfway position; 2) a base that is irregularly broken instead of straight across; 3) a blunt apex; and 4) a circular cross-section and no occlusal crest (many of the illustrated triangle with parallel inline specimens appear to have an occlusal crest, lateral flanges, and an acute lateral cross-section. This specimen has pitting and weak striations on the outer surface that may have resulted from abrasion or other alteration processes. The presence or absence of a ridged/flanged occlusal crest may help to recognize two different subtypes in future studies. Triangle with parallel inline occurs erratically throughout the Cenozoic (Doyle and Riedel 1979a, p. 120).
Occurrence: 1 specimen; near Matlahaw Point, Hesquiat Peninsula; Oligocene.
cf. small triangle long striations
Dunsworth et al. 1975, p. 857
Figure 67
a9/b1/c1/d1/e1/f(4a+b)+9+(12,13)+(14,15)/g1/h1,4,5/i3/j6/k0,1,5/m0/n1.4-1.7/p0/q2,9,10/r0,1/s1,2,3/t2/z0
Characters: Tooth with long internal striations that extend from base to about three-quarters tooth height; many striations approximately vertical or may depart from centre at about 45° or more; one margin slightly concave, other margin slightly convex; flares basally and curvature slightly asymmetric; apex rounded to acute; outline smooth; inline low arcuate or absent; with shadow; base irregularly broken to straight; height/width 1.4-1.7:1; circular cross-section; no transverse line; no occlusal crest.
Remarks: The Tofino Basin Shell-Anglo specimens differ from small triangle long striations Dunsworth et al. 1975 by having tooth crown shadow and a concave and convex margin (instead of straight margins). Small triangle long striations are known to occur in the lower Miocene to Quaternary (Dunsworth et al. 1975).
Occurrence: 2 specimens; offshore wells Shell-Anglo Cygnet J-100 and Zeus D-14; Bulbous Base ichthyolith Zone; middle to upper Miocene.
cf. striated triangle
Ramsey et al. 1976, p. 132-133
Figure 68
a9/b1/c1/d1/e1/f9+12+14/g1/h2/i2,3,4/j2,3/k0,5/m0/n>2/p0/q6,10/r0,1/s1/t2/z0
Characters: Tooth triangular and cone-shaped; with no occlusal crest ridge or flange; circular in cross-section; with internal striations that extend into upper crown and may originate near tooth base; basal crown opaque; base irregularly broken but somewhat curved; one basal margin region lower than other; both margins straight or slightly evenly to basally convex; taller than wide (ratio >2:1); apex approximately sharp.
Remarks: This specimen differs from striated triangle by being taller (height/width >2), having an irregularly broken base without a transverse line, and having an opaque basal region. Striated triangle has been recorded from the Upper Jurassic through Eocene (Doyle and Riedel 1979a, p. 134).
Occurrence: 1 specimen; near Matlahaw Point, Hesquiat Peninsula; Oligocene.
cf. curved triangle, parallel-sided inline new subtype
Figure 69
a9/b1,5/c1/d1/e1/f1/g1/h0/i0,1/j0,1/k0,1/m0/n0/p0/q0/r0/s0/t2/z0,2/cc1,7/dd1,7/ee1/ff1/gg1,7/hh0/jj4/kk3,4,5/mm0/nn0
Characters: Tooth with cap missing. Tooth base: with long, central, thread-like parallel-sided inline; with rim and socket at base; circular in cross-section; one margin concave; second margin concave, convex, or sigmoid; may have faint vertical lines on basal outline.
Remarks: These Shell-Anglo specimens differ from curved triangle, parallel sided inline new subtype by having a thinner thread-like inline and a prominent rim and socket base. The curvature of the tooth cannot be determined because the tooth cap is missing on all specimens.
Occurrence: 10 specimen fragments, 6 questionable specimens; offshore wells Shell-Anglo Apollo J-14, Cygnet J-100, Pluto I-87, Prometheus H-68, and Zeus D-14; offshore core END-76B-6; and Hesquiat Peninsula; Miocene and lower Pliocene; possibly upper Oligocene.
small pointed triangle
Tway et al. 1985, p. 306
Figure 70
a9/b1,5/c1/d1/e1/f1/g1/h4,5/i6/j3/k8+9/m0.4-0.7/n1.4-1.7/p0/q6,7,10/r1/s1,2/t2/z0
Remarks: These Tofino Basin teeth are small and triangular, circular in cross-section, and have a height to width ratio of about 1.4–1.7:1. One tooth margin is evenly concave and the other evenly convex. The apex is moderately pointed and may have apical shadow. The tooth base is irregular, and a transverse line may be present (very faint). Two inlines have a similar shape to the outline, the outermost is at the outline margin and very close to the apex outline, and the innermost is cone-shaped, one-half to two-thirds the height of the tooth and not close to outline. The tooth base is centrally recessed (convex-up).
Tway et al. 1985 remarked that this subtype occurred in the upper Oligocene, and in undated samples it ranged from the middle Eocene through upper Oligocene. The Tofino Basin specimens may be reworked from older Oligocene sediments or at the top of the subtype range in the Miocene.
Occurrence: 2 specimens; offshore well Shell-Anglo Apollo J-14; reworked from ?Oligocene strata, deposited into middle/upper Miocene to lower Pliocene.
cf. curved triangle wide inline new subtype
Figure 71
a9/b1,5/c1/d1/e1/f1/g1,3,8/h0/i0/j0/k0/m0/n0/p0/q0/r0,1/s0/t2/z0,2/cc1,7/dd1,7/ee1/ff0,1,3/gg1,7/hh0/jj3/kk4/mm0/nn0
Characters: Tooth base with cap missing; commonly breaks straight across. Base curved, one concave and one convex margin; inline wide, similar shape to outline, commonly close to outline; circular cross-section; basal rim present on some specimens; outline smooth, lightly pitted, or with irregular lines; height to width ratio may be >3.
Remarks: These specimens are taller and narrower than curved triangle wide inline and the base is not as flared. The inline is a similar shape to the outline, commonly close to the outline, and opaque.
The figured specimen (Figure 71.1.1) shows a narrow inline. Many specimens have a wider inline that is closer to the outline (Figure 71.2.1) but they were hard to photograph because they are dark or opaque.
Occurrence: 11 fragments, 13 questionable fragments; offshore wells Shell-Anglo Cygnet J-100, Prometheus H-68, and Zeus D-14; Bulbous Base ichthyolith Zone; Miocene and lower Pliocene; possibly upper Oligocene.
curved triangle wide inline new subtype
Figure 72
a9/b1,5/c1/d1/e1/f1,4a+b/g1,3,6,8/h0,1,5/i3/j6,9/k0/m1.8-3.0/n1-2/p0/q0/r0/s1,2/t2/z0,2/ cc0,1,7/dd0,1,7/ee1/ff1/gg1,4,7,8/hh1.8-3.0/jj3/kk4/mm1.5-2.5/nn0.15-0.5
Characters: Tooth curved with one concave and one convex margin; flares slightly at base and may have thin rim; outline weakly stippled, pitted, or with weak vertical or irregular lines; circular cross-section; height to width ratio >1. Inline only in base below cap and transverse line; moderately close to outline, cone-shaped or irregular cone-shaped to acuminate near apex. Tooth apex conical; transparent or may have shadow; commonly missing from base; inline absent; outline smooth (no occlusal crest, no ornament); margins straight, convex or concave; apex acute. Transverse line faintly visible or absent.
Remarks: Long triangle thin wall Dunsworth et al. 1975 has a small cap, a base inline close to the outline, and a transverse line that is straight across much like curved triangle wide inline, however, it differs by not having distinctly curved concave/convex margins and the tooth base height is greater (≥4). Long triangle thin wall occurs in the lower Eocene through lower Miocene (Doyle and Riedel 1979a, p. 180).
The Shell Canada specimens have some similarities to short triangle stepped margin Doyle et al. 1974 by having a similar inline, tooth shape, and tooth cap. They differ by not having the stepped margin at the transverse line and by having a shallow rim at the tooth base. A similar undescribed form (Doyle and Riedel 1985b, Figure 25-5, p. 987) was found to be co-occurring with short triangle stepped margin and also lacks the stepped margin like the Shell Canada specimens. Short triangle stepped margin occurs near the Oligocene-Miocene boundary through the Quaternary.
Curved triangle wide inline differs from Shell Canada specimens narrow curved triangle Doyle et al. 1974 by not having a narrow and parallel-sided inline. Also, they differ from cf. narrow curved triangle Doyle et al. 1974 by not being flattened with an oval cross-section and by not having a reverse-stepped cap/base margin.
Occurrence: 5 specimens, 7 fragments, 2 questionable fragments; offshore wells Shell-Anglo Apollo J-14, Cygnet J-100, Pluto I-87, Prometheus H-68, and Zeus D-14; offshore core END-76B-6D; Bulbous Base ichthyolith Zone; Miocene, lower Pliocene, and possibly upper Oligocene.
narrow tall triangle, cone inline new subtype
Figure 73
a9/b1,5/c1/d1/e1/f4a+b/g1/h0/i2,3/j2,6/k0/m0/n>1/p0/q0/r0/s1,2/t2/z2/cc1,7/dd1,7/ee1/ff1/gg1,7/hh>3/jj2,3,5/kk2,4,5/mm2.5-3.5/nn≤0.2
Characters: Tooth narrow and tall (height/width ≥3), moderately erect; margins sigmoidal; with rim base; transverse line straight across at base of cap. Inline only in base, irregular cone-shaped; commonly extends one-third or more up from base; occasionally with a few irregular threads that extend from cone tip upwards towards cap. Base with sigmoid or curved margins or one margin convex and other concave; gradually widens (from apex to base) except near base with constriction above a wider basal rim; circular cross-section. Cap with acute apex; may be shadowed; one margin convex or straight; other margin concave or straight; height slightly greater than width; inline absent.
Remarks: Narrow tall triangle, cone inline has a distinct base with a cone inline greater than one-third the height of the base and a basal rim. The tooth is tall and narrow (height/width: ≥3). Narrow tall triangle cone inline is most similar to curved triangle wide inline new subtype but is taller and narrower and lacks prominent concave/convex curvature and instead has sigmoidal margins.
Occurrence: 1 specimen, 7 fragments; offshore wells Shell-Anglo Cygnet J-100, and Zeus D-14; Bulbous Base and Shadowed Cone ichthyolith zones; Miocene and Pliocene.
narrow tall triangle, inflated inline apex new subtype
Figure 74
a9/b1,5/c1/d1/e1/f4a+b/g1/h0/i2,3/j2,6/k0,5,8/m0/n0/p0/q0/r0/s1,3/t2,3/z2/cc1,7/dd1,7/ee1/ff1/gg4,7/hh>4/jj5/kk5/mm2/nn0.125
Characters: Tooth narrow and tall (height/width ≥5); with rim and socket base; transverse line straight across at base of small cap. Base with sigmoid margins; slightly inflated basally and apically; flattened oval to circular cross-section. Base inline prominent and long, commonly parallel-sided basally and slightly inflated apically. Cap small (equal to or slightly taller than tooth maximum width); with shadow; one margin convex or straight; other margin concave or straight; apex acute or rounded; inline absent or arcuate (extension of base inline).
Remarks: Narrow tall triangle, inflated inline apex differs from angled cone and bulbous base new subtype by not having a bulbous base (the upper base is only slightly inflated) and by not having a cap base width at the transverse line that is distinctively narrower than the inflated/bulbous region of the tooth base apex. Also, the base inline near the apex of the two subtypes is different; angled cone and bulbous base has a spray/flower-like apical inline instead of the slightly inflated bulbous-like shape of the tooth base apical inline of narrow tall triangle, inflated inline apex.
Occurrence: 4 specimens, 10 fragments, 8 questionable specimens; offshore wells Shell-Anglo Apollo J-14, Cygnet J-100, Pluto I-87, Prometheus H-68, and Zeus D-14; and offshore core END-76A-6E; long ranging; upper Eocene/Oligocene through Pliocene.
narrow tall triangle, irregular threaded inline new subtype
Figure 75
a9/b1,5/c1/d1/e1/f4a+b/g1/h0/i2,3/j2,6/k0,8/m0/n~2/p0/q0/r0/s1,3/t2,3/z2/cc1,7/dd1,7/ee1/ff1/gg1,7/hh>4/jj3,5/kk4,5/mm1.8-2/nn0.20-0.25
Characters: Tooth narrow and tall (height/width ≥5); with rim and socket base; transverse line straight across at base of cap. Base with sigmoid margins or one margin convex and other concave; gradually widens (from apex to base) except near base with constriction above a wider basal rim; circular cross-section to slightly oval. Basal tooth base with small parallel-sided inline or cone-inline, commonly in basal one-quarter. Upper tooth base inline with irregular threads approximately parallel to outline and commonly extend to cap base. Cap dark with shadow; one margin convex or straight; other margin concave or straight; apex acute to rounded; height >2 times width; inline absent or high-shadowed.
Remarks: Narrow tall triangle, irregular threaded inline has a distinctive threaded base inline with a small basal cone or parallel-sided inline. The tooth is tall and narrow with a basal rim. The tooth base is not significantly inflated just below the cap. It differs from narrow tall triangle inflated inline apex new subtype by not having the inflated inline apex.
Occurrence: 1 specimen, 6 fragments, 1 questionable specimen, 2 questionable fragments; offshore wells Shell-Anglo Cygnet J-100, Pluto I-87, Prometheus H-68, and Zeus D-14; and Flores Island (outcrop sample); long ranging; upper Eocene/Oligocene through Pliocene.
cf. long triangle stepped margin
Doyle et al. 1974
and
cf.
angled cone and bulbous base new subtype; "shadowed high inline cone"
Figure 76
a9/b1,5/c1/d1/e1/f4a+b/g1/h0/i6,7,9/j2,4,7,9/k8/m<0.1/n1.5-2.5/p0/q0/r0/s1,2/t2/z2/
Characters: Tooth cone-shaped, height to width ratio about 1.5-2.5:1; circular cross-section; base wide and flared with equal length margins at straight-across transverse line. Cap apex moderately acute (not blunt or sharp); one margin concave or basally concave; other margin convex, sigmoid, basally concave, or straight; with apical and lateral dark shadows (enough to blacken cone), no occlusal crest. Inline same shape as outline; dark or black; high into apical region; base recessed (convex-up). No tooth base observed.
Remarks: The Shell-Anglo specimens differ from other similar subtypes: curved flared triangle, flared triangle arcuate inline, triangle arcuate inline, straight flared triangle, and tall triangle low inline (Ramsey et al. 1976 p. 130-132) by having a high inline, and dark shadowing of the inline and areas between the inline and outline.
Shadowed high inline cone differs from shadowed curved blunt triangle new subtype by being distinctly cone-shaped with a more acute apex, a wide or flared base, a circular cross-section, and a straight-across transverse line. Also, margin curvature is less than shadowed curved blunt triangle.
Shadowed high inline cone teeth (without bases) are indistinguishable from the caps of cf. long triangle stepped margin Doyle et al. 1974 and angled cone and bulbous base new subtype. Shadowed caps of cf. long triangle stepped margin commonly have a height to width ratio of 2:1 and a moderately acute cap. Shadowed caps of angled cone and bulbous base commonly have a height to width ratio ≤2:1 and have a rounded apex. All these caps are in within the range of cf. long triangle stepped margin and within the upper range of angled cone and bulbous base in upper Miocene to Pliocene Tofino Basin sediments.
Occurrence: 11 specimens; offshore wells Shell-Anglo Apollo J-14, Cygnet J-100, and Prometheus H-68; Shadowed Cone ichthyolith Zone; Pliocene and upper Miocene; possibly middle Miocene.
shadowed curved blunt triangle new subtype
Figure 77
a9/b1,5/c1/d1/e1/f4a+b/g1/h0,1,5/i6,7/j2,3,9/k8,9/m0/n>2/p0/q0,6,7/r0,1/s1,3,4/t3/z0,2
Characters: Tooth triangular with slight or no basal flare; height to width ratio >2, may be >3; flattened to rounded elliptical cross-section; apex rounded, blunt or truncate; one margin concave, other margin convex or sigmoid; with no occlusal crest; with dark apical and lateral shadows (enough to blacken cone); base straight-across transverse line or irregular but no great difference in margin lengths; inline same shape as outline, high into apical region, close to outline at base, and base recessed (convex-up). No tooth base observed.
Remarks: The Shell-Anglo specimens differ from narrow straight triangle Doyle and Riedel 1985b by having margin curvature, a slightly flared base, elliptical to oval cross-section, prominent shadow, and a height to width ratio commonly >2. They share in common the high inline, rounded apex, and a basal transverse line. Narrow straight triangle ranges from upper Paleocene through earliest Eocene (Doyle and Riedel 1985b).
Occurrence: 10 specimens, 2 fragments; offshore wells Shell-Anglo Apollo J-14, Cygnet J-100, and Zeus D-14; Shadowed Cone ichthyolith Zone; Pliocene and upper Miocene; possibly middle Miocene.
dome-top triangle bowed inline new subtype
Figure 78
a9/b1,5/c1/d1/e1/f4a±b/g1/h0,1,5/i6,9/j6,9/k3/m0.05-0.25/n1.5-2/p0/q0,2/r0,1/s3/t2,3/z0,2
Characters: Tooth triangular and cone-shaped; with blunt/rounded shiny dome-top cap, flared base, and no flanged occlusal crest; outer inline bowed-in, close to outline at base, and apically close to outline apex (>three-quarters tooth height); interior inline parallel-sided with a slightly inflated apex or may be a second shorter bowed-in structure; circular to obtuse in cross-section; taller than wide (ratio 1.5-2.0:1); both margins sigmoidal, slightly concave, or straight; transverse line straight across at tooth base; shadow common in inline and between inline and outline.
Remarks: Dome-top triangle bowed inline is distinct with its blunt and shiny dome-top and its tall outer bowed inline and shorter inner bowed inline or apically inflated parallel inline.
Occurrence: 7 specimens, 1 questionable specimen; Hesquiat Peninsula; Centrally Inflated Triangle With Canals ichthyolith interval; upper Eocene and Oligocene.
curved triangle, striated inline new subtype
Figure 79
a9/b1,5/c1/d1/e1/f(4a+b)+(8,9)+(11,12)+14/g1,3,8/h0,1,5/i2,3/j2,6/k0,1,7,11/m0/n1-1.5/p2.0-3.5/q0,2/r0,1/s2,3/t2/z0,2/cc1,7/dd1,7/ee1/ff2/gg1,4,8/hh2.5-3.5/jj3/kk4/mm1.5-4/nn0.1-0.3
Characters: Tooth evenly curved, one margin convex, other margin concave; margin lengths similar; base may have shallow rim; circular cross-section; height to width about 2-3.5:1. Inline solid and close to outline at base, commonly with central parallel-sided inline; extends up tooth >one-half (commonly two-thirds to three-quarters); with irregular apex and striations. Inline striations common (may cover most of inline apex), approximately vertical, and not long (do not extend to tooth cap). Outline smooth, lightly pitted, or with faint irregular striations. Tooth cap without inline; commonly with shadow and straight margins; apex acute to rounded; transverse line straight across; height/width ≥1:1.
Remarks: These specimens are distinct by having tooth concave-convex curvature, inline striations, and a parallel-sided inline. Curved triangle, striated inline mainly differs from narrow curved triangle small top Ramsey et al. 1976 by not having the small apical cap; narrow triangle ragged base Dunsworth et al. 1975 by not having the ragged base, and curved flared triangle Ramsey et al. 1976 by having a greater height to width ratio (>2:1) and not having an inline that is a similar shape to the outline.
Occurrence: 7 specimens, 2 questionable fragments; offshore wells Shell-Anglo Prometheus H-68 and Zeus D-14; Striated Triangle ichthyolith Zone; lower to middle Miocene.
cf. curved flared triangle
Ramsey et al. 1976, p. 130
Figure 80
a9/b1,5/c1/d1/e1/f(4a+b)±10±11±14/g1±7/h0/i6,7/j3/k3,8/m0.5-0.6/n1.8-2.0/p0/q0/r0/s3/t2/z2
Characters: Tooth triangular; height to width ratio about 2-3:1; circular in cross-section; one margin basally concave; other margin evenly convex; apex rounded; with apical and lateral shadow; transverse line straight across at base; inline in bottom one-half to one-third, similar shape to outline or slightly bowed-in, not close to outline; with a few striations on inline apex.
Remarks: The Shell-Anglo specimen differs from curved flared triangle by having apical and lateral shadow, a rounded apex, an inline with a similar shape to the outline instead of arcuate, and inline height that is > one-quarter ≤one-half the height of the tooth. It is similar by having convex and concave margins, and striations between the inline and outline. Curved flared triangle occurs in the Upper Jurassic through middle Eocene (Doyle and Riedel 1979a, p. 102).
Occurrence: 2 specimens; offshore well Shell-Anglo Pluto I-87; upper Eocene/Oligocene, ?reworked from older strata.
curved triangle, parallel-sided inline new subtype
Figure 81
a9/b5/c1/d1/e1/f4a+b/g1/h0/i2,3/j2,6/k0/m0/n<1.5/p0/q0/r0/s1,2,3/t2/z2/cc1,7/dd1,7/ee1/ff1,2/gg4/hh>2/jj3/kk4/mm2-4/nn0.16-0.36
Characters: Tooth moderately robust with curved base and conical cap; transverse line straight across; parallel-sided inline of variable length but always in base below cap and transverse line; shadow common in cap and base; circular cross-section. Tooth base with one margin convex and the other concave; faintly stippled outline; maximum height 3 to 5 times maximum width; may have basal rim and socket. Tooth cap small; about as tall as wide or height ≤1.5 times width; one margin concave or straight, second margin convex or straight; may be one-third to one-sixth height of base; no internal features; outline not ornamented.
Remarks: This new subtype differs from narrow curved triangle Doyle et al. 1974 by having a variable length parallel-sided inline that is below the transverse line, a small cap with a height to width ratio ≤1.5, and a base with a faintly stippled outline. This new subtype differs from curved triangle long top Gupta 1991 by not having a long parallel-sided inline that extends to the transverse line.
Occurrence: 7 specimens, 5 fragments, 11 questionable fragments; offshore wells Shell-Anglo Apollo J-14, Cygnet J-100, Pluto I-87, Prometheus H-68, and Zeus D14; long ranging; Bulbous Base ichthyolith Zone; Miocene and Pliocene; possibly upper Eocene/Oligocene.
cf. narrow curved triangle
Doyle et al. 1974, p. 847;
Doyle and Riedel 1979a, p. 187
Figure 82
a9/b5/c1/d1/e1/f4a+b/g1/h0/i2,6/j2,3/k0,1,12/m>2<2.5/n2-3/p0/q0/r0/s1,2/t3,2/z2/cc1/dd1/ee1/ff1,2/gg1,4/hh2-2.5/jj4/kk3/mm~2/nn0.4-0.45
Characters: Tooth triangular, curved, and with no occlusal crest; first margin concave and second margin convex; transverse line straight across; base reverse-stepped (cap base significantly wider than tooth base apex); oval to circular cross-section. Tooth base inline tall (in upper two-thirds to three-quarters) and narrow cone-shaped; similar shape to outline but not near outline; with acute apex that may thin to a thread and may extend into cap. Tooth base curved, commonly longest margin convex, other margin concave; occasional both margins same length; outline weakly stippled or textured; with irregular to ragged base. Tooth cap apex acute; height to width ratio >2<2.5; unornamented/smooth; transparent or with shadow; one margin concave or straight, other margin convex or straight.
Remarks: The Shell-Anglo specimens differ from narrow curved triangle by not having a cap height/width ratio ≥2.75, much of the inline (only thread-like) above the transverse line, and an outline longitudinal line, and by having a reverse stepped margin at the cap/base junction, cap apical shadow on some specimens, and an oval cross-section and slightly flattened tooth.
Narrow curved triangle is known to occur in the deep-sea upper Oligocene through lower Miocene and two specimens have been found in the upper Eocene or lower Oligocene (Doyle and Riedel 1979a, p. 186).
Occurrence: 2 specimens, 16 fragments, 6 questionable fragments; offshore wells Shell-Anglo Cygnet J-100, Prometheus H-68, and Zeus D-14; Bulbous Base ichthyolith Zone, common in the middle to upper Miocene, a few in the lower Miocene, and rare in the Pliocene.
cf. short triangle stepped margin
Doyle et al. 1974, p. 847;
Doyle and Riedel 1979a, p. 183
Figure 83
a9/b5/c1/d1/e1/f±4a±b/g1/h0/i2,6/j2,3,6/k0/m0/n<2/p0/q0/r0/s0,1,3/t2/z3/cc1/dd1/ee1/ff1/gg3,7/hh~2/jj2,3,5/kk2,3/mm1.5-2.5/nn0.4-1.0
Characters: Tooth cap and base separated by a transverse line that forms a stepped margin. Tooth cap conical; height to width ratio <2; outline smooth (no occlusal crest, no ornament); margins straight, convex, or concave; with apical shadow; apex acute to rounded. Tooth base margins straight, sigmoid, or convex near transverse line; inline similar shape to outline, restricted to within base, with somewhat parallel margins and not near outline margins; outline with weakly vertical and irregular striations; circular cross-section; height to width ratio about 2:1.
Remarks: The stepped margin near the transverse line and the short height to width ratio of the tooth cap are distinguishing features of this subtype. The Shell-Anglo specimen differs by having apical shadow in the cap, faint vertical and irregular striations on the tooth base outline, and a shorter inline that is only present in the tooth base. Short triangle stepped margin occurs near the Oligocene/Miocene boundary through the Quaternary (Doyle and Riedel 1979a, p. 182).
Occurrence: 3 specimens, 3 questionable specimens; offshore wells Shell-Anglo Apollo J-14, Pluto I-87, and Zeus D-14; Bulbous Base ichthyolith Zone; mainly Miocene; possibly Pliocene.
cf. long triangle stepped margin
Doyle et al. 1974, p. 847;
Doyle and Riedel 1979a, p. 185
Figure 84
a9/b5/c1/d1/e1/f4a+b/g1/h0/i2,7,9/j2,3,9/k0,1,8/m0/n1.5-3/p0/q0/r0/s2/t2/z3/cc1,7/dd1,7/ee1/ff1,2,3/gg4,7/hh1.5-3/jj4/kk3/mm1.5-2.5/nn0.2-1.0
Characters: Tooth curved; cap and base separated by a transverse line that forms a slightly stepped margin. Tooth cap conical; height to width ratio >1.5, commonly ≥2; outline smooth (no occlusal crest, no ornament); margins straight, concave basally, or slightly convex or sigmoid; with dark apical shadow; apex acute. Tooth base with shallow basal rim; outline well textured with stippling and irregular lines (especially basally); one margin concave or sigmoid, other margin convex or sigmoid; striations common in upper tooth base and below transverse line; inline hard to determine (well shadowed in region below striations); circular cross-section; height to width about 2:1.
Remarks: The curved tooth, slightly stepped margin near the transverse line, >1.5 and commonly ≥2 height to width ratio of the tooth cap, and the moderately acute cap apex are distinguishing features of this subtype. The Shell-Anglo specimens mainly differ by not having a well-developed stepped margin, and having a dark shadowed cap, base inline striations, a shallow base rim, and a stippled and textured base outline. The textured base and rim and the dark cap are similar to angled cone and bulbous base but these specimens do not have the bulbous base and a flower-like inline. Long triangle stepped margin occurs in latest Miocene to Recent (Doyle and Riedel 1979a, p. 184).
Occurrence: 5 specimens; offshore wells Shell-Anglo Apollo J-14, Cygnet J-100 and Prometheus H-68, and offshore core END76B-6C; Shadowed Cone ichthyolith Zone; upper Miocene and Pliocene.
angled cone and bulbous base new subtype
Figure 85
a9/b5/c1/d1/e1/f4a+b/g1/h0/i6,9/j2,3,9/k8/m0/n<2.5/p0/q0/r0/s1,3/t2/z2/cc6,7/dd6,7/ee1/ff1/gg1,4/hh>1.5/jj5/kk5/mm1-2/nn0.3-0.5
Characters: Tooth with a bulbous base just below a curved triangular cap; cap and base separated by a transverse line. Tooth cap outline smooth (no occlusal crest, no ornament); angled onto base; one margin concave or sigmoid, second margin convex or straight; inline greatly shadowed dark or black, high in cap (>three-quarters cap height); apex bluntly rounded to moderately acute (in narrower, less bulbous specimens); circular cross-section; commonly missing from base. Tooth base bulbous-shaped (widens from cap base, then narrows basally, then widens slightly at tooth base to form a rim); inline variable (may be a flower-like spray, basally parallel to outline, thread-like, or broken); inline base may have central basal projection below outline (socket-like?); margins sigmoid-shaped; outline smooth except in most basal region may be stippled or rough-textured; circular cross-section. Tooth cap height/width commonly <2, rarely >2<2.5; tooth base height >1.5 times height of tooth cap.
Remarks: This new subtype is characterized by the bulbous nature of the tooth base, and the angled, prominently shadowed, and curved cap. The bulbous and elongate character may indicate a pharyngeal tooth form. Some teeth (5 specimens and 2 fragments) are taller and narrower and the bulbous nature of the base is not as developed (but still present); the cap is not as darkly shadowed, is taller than wide, and has a moderately acute apex but it still sits at an angle on the base, and has one concave or sigmoid margin and one convex or straight margin.
An undescribed form (Dengler et al. 1975; Plate 5, fig. 5) shows a similar bulbous character but has a different inline that is broad and extends from the base into the cap.
Occurrence: 23 specimens, 33 base fragments, 10 cap fragments; 3 questionable specimens; offshore wells Shell-Anglo Apollo J-14, Cygnet J-100, Prometheus H-68, and Zeus D-14; offshore cores END-76B-5 & END-76B-6; Bulbous Base ichthyolith sub-assemblage, mainly Miocene; some in the Pliocene; possibly in the upper Oligocene (may be reworked).
cf. triangle small top Ramsey et al. 1976, p. 132;
Doyle and Riedel 1979a, p.167
Figure 86
a9/b5/c1/d1/e1/f4a+b/g1/h0,1,5/i2,3/j2/k0/m0/n~1/p0/q0/r0/s1,2/t2,3/z2/cc1/dd1/ee1/ff3/gg1,4,7/hh1.4-2.0/jj5/kk3/mm2.0-2.5/nn<0.18
Characters: Tooth triangular with a small cap; height of cap about 1/6 height of base. Cap with shadow, margins straight, height to width ~1:1; apex sharp; transverse line straight across; inline absent. Base with one sigmoid and one convex margin; width at base about 2-2.5 times width at transverse line (basally widens); inline generally solid and near outline; striations may be present above inline apex; circular to oval cross-section; may have outline stippling and irregular lines.
Remarks: The Shell-Anglo specimen differs from triangle small top by having apical shadow, a base inline near the outline, base striations above inline apex, and stippling and irregular lines on the base outline. Triangle small top occurs in the Cretaceous through Quaternary (Doyle and Riedel 1979a, p. 166).
Occurrence: 3 specimens; offshore wells Shell-Anglo Prometheus H-68 and Zeus D-14; and offshore core END-76B-6A; Striated Triangle ichthyolith Zone; middle to lower Miocene.
cf. triangular triangle Kozarek and Orr 1980, p. 873
Figure 87
a9/b5/c1/d1/e1/f4b/g1/h0/i2,6/j2,3/k0/m0/n>1/p0/q0/r0/s0/t2/z2/cc1/dd1/ee1/ff1/gg1/hh>3/jj2,4/kk2,3/mm1.5/nn0,0.25-0.35
Characters: Tooth tall, narrow, and transparent; height to width ratio >4; cap and base separated by a straight-across transverse line. Tooth cap conical; height to width ratio about >1:1; with apical shadow; margins straight or slightly concave or convex; outline smooth; inline absent. Tooth base with circular cross-section; height to width ratio >3; margins straight or slightly concave or convex; outline smooth; inline absent or very low arcuate; some faint shadow zones.
Remarks: The Shell-Anglo specimen differs from triangular triangle Kozarek and Orr 1980 by having a transverse line, a circular cross-section (not triangular), and a height to width ratio >5. However, Plate 6, Fig. 10 (Kozarek and Orr 1980) appears to illustrate a tooth height/width ratio >5 and a circular cross-section that is different from the description. Triangular triangle ranges in the Oligocene to Quaternary (Kozarek and Orr 1980).
Occurrence: 1 specimen; offshore well Shell-Anglo Apollo J-14; middle Miocene.
Undescribed cone tooth, Form A
Figure 88
a9/b1/c1/d1/e1/f9+12+15+22/g1/h3/i3,10/j6,10/k7/m0/n>2.5/p0/q9,10/r1/s3/t2/z0
Remarks: This tooth has many inline to outline striations that radiate from a parallel-sided inline, the cap is small, and the margin curvature is sigmoidal, convex, or concave.
Occurrence: 3 specimens; offshore well Shell-Anglo Apollo J-14 and core END-76B-6A; middle Miocene.
Undescribed cone tooth, Form B
Figure 89
a9/b1,5/c1/d1/e1/f1/g1,6,8/h0,1,5/i2,3/j2,6/k1/m0/n1,2.8/p0/q2,9/r0,1/s1/t2/z0,2/cc0,1/dd0,1/ee0,1/ff0/gg0,3,7/hh1.8/jj3/kk4/mm2.9/nn0.19
Remarks: This tooth is characterized by convex/concave margins and common vertical lines on the outline especially in the basal two-thirds of the tooth. The upper part of the tooth is smooth and unornamented with a possible small conical tooth cap (arrow shows possible transverse line).
Occurrence: 1 specimen; offshore well Shell-Anglo Pluto I-87; Oligocene.
Undescribed cone tooth, Form C
Figure 90
a9/b1,5/c1/d1/e1/f4a+b/g1/h0,1,5/i2/j2/k0/m0/n>1.5/p0/q0,2/r0,1/s1,2/t2/z0,2
Remarks: This tooth is characterized by straight margins, an acute apex, apical shadow, and no significant inline in the cap.
Occurrence: 4 specimens; offshore wells Shell-Anglo Cygnet J-100, and Zeus D-14; Miocene and Pliocene.
Undescribed cone tooth, Form D
Figure 91
a9/b1,5/c1/d1/e1/f4a+b/g1/h0,1,5/i2,3,5/j6,8/k3+9/m0.25/n3.2/p0/q0,2/r0,1/s1,2/t2/z0,2
Remarks: This tooth is characterized by apical convex/concave margins, a tall cone apex, and a tall and bowed inline.
Occurrence: 1 specimen; offshore well Shell-Anglo Cygnet J-100; Pliocene.
Undescribed cone tooth, Form E
Figure 92
a9/b1,5/c1/d1/e1/f4a+b/g1/h0,1,5/i2,5,3,9,10/j2,6,9,10/k0,1/m0/n≥1, ≥3/ p0/q0,2/r0,1/s3/t2/z0,2
Remarks: This tooth is characterized by a dark shadowed cap, sigmoidal margins, and an irregular possibly parallel-sided inline.
Occurrence: 1 specimen; offshore well Shell-Anglo Cygnet J-100; Pliocene.
Undescribed cone tooth, Form F
Figure 93
a9/b1,5/c1/d1/e1/f4a+b/g1/h0,1,5/i3/j6/k0/m0/n>1.5/p0/q0,2/r0,1/s1,2/t2/z0,2
Remarks: This tooth is characterized by convex/concave margins, an acute apex, apical shadow, and no significant inline in the cap.
Occurrence: 3 specimens; offshore wells Shell-Anglo Apollo J-14, Cygnet J-100, and Prometheus H-68; Pliocene and Miocene.
Undescribed cone tooth, Form G
Figure 94
a9/b1,5/c1/d1/e1/f4a+b/g1/h0,1,5/i3,5/j6,8/k8,9/m0.13/n2.9/p0/q0,2/r0,1/s1,3/t2/z0,2
Remarks: This tooth is characterized by some apical convex/concave margins, and a cone inline.
Occurrence: 1 specimen; offshore well Shell-Anglo Pluto I-87; upper Eocene/Oligocene.
Undescribed cone tooth, Form H
Figure 95
a9/b1,5/c1/d1/e1/f4a+b/g1/h0,1,5/i3,9,10/j6,9,10/k3,8,9/m0/n2-4/ p0/q0,2/r0,1/s1,2/t2/z0,2
Remarks: This tooth is characterized by sigmoidal margins, a tall shadowed cone apex, and a bowed inline.
Occurrence: 1 specimen; offshore well Shell-Anglo Cygnet J-100; Pliocene.
Undescribed cone tooth, Form I
Figure 96
a9/b1,5/c1/d1/e1/f4a+b/g1/h0,4/i4,9,10/j6,10/k0/m0/n>1.5/p0/q0,2/r0,1/s1,2/t2/z0,2
Remarks: This tooth is characterized by sigmoidal margins and no significant inline.
Occurrence: 1 specimen; offshore well Shell-Anglo Apollo J-14; ?Miocene.
Undescribed cone tooth, Form J
Figure 97
a9/b1,5/c1/d1/e1/f(4a+b)±8/g1/h0,1,5/i2,9,10/j2,9,10/k7/m0/n≥1/p0/q0,2/r0,1/s1/t2/z0,2
Remarks: This tooth is characterized by slightly stepped margins (arrows) and a parallel-sided inline in the tooth base.
Occurrence: 1 specimen; offshore well Shell-Anglo Cygnet J-100; lower Pliocene.
Undescribed cone tooth, Form K
Figure 98
a9/b1,5/c1/d1/e1/f(4a+b)+8/g1/h1,5/i9,10/j9,10/k0,1/m0/n>2/p0/q0,2/r0,1/s3/t2/z0,2
Remarks: This tooth is characterized by sigmoidal margins and striations in the tooth base.
Occurrence: 1 specimen; offshore well Shell-Anglo Zeus D-14; middle to upper Miocene.
Undescribed cone tooth, Form L
Figure 99
a9/b1,5/c1/d1/e1/f(4a+b)+9+11+(14,15)/g1/h0,4/i5/j8/k8,9/m0/n>1,>2/p0/q0,2/r0,1/s1/t2/z0,2
Remarks: This tooth is characterized by many striations between the inline and outline (in the cap base) and convex/concave margin and tooth curvature.
Occurrence: 1 specimen; offshore core END-76B-6C; ?Miocene.
Undescribed cone tooth, Form M
Figure 100
a9/b5/c1/d1/e1/f4a+b/g1/h0,1,5/i5/j8/k5,8,9/m0.13/n2.5/p0/q0,2/r0,1/s3/t2/z2
Remarks: This tooth is characterized by apical convex/concave margins, cone inline, common apical shadow, and a cylindrical or tubular base.
Occurrence: 1 specimen; offshore well Shell-Anglo Prometheus H-68; Pliocene.
