Tofino Basin flanged teeth are triangular-shaped and have a cutting edge (occlusal crest) that traverses the apex and tooth crown margins and may traverse the tooth base margins
(Figure 47). At the tooth margins, the occlusal crest may be broad or flanged. Important characteristics of the occlusal crest or flange include thickness apically and basally, curvature, and termination at the transverse line or the base of the tooth.
Flanged teeth with canals are included in the triangular teeth with inline canals group.
Damaged flanged teeth (8 specimens) were mainly from the Pluto I-87 well and the base of the Zeus D-14 well (Oligocene or upper Eocene). They could be specimens of triangle double flex, centrally inflated triangle with canals, or narrow triangle straight inbase.
triangle chisel-top new subtype
cf. triangle notched corner Doyle et al. 1974
beveled triangle high inline Doyle et al. 1978
cf. triangle bowed inline Ramsey et al. 1976 emend. Doyle and Riedel 1979a,
triangle modified margin ends Doyle and Riedel 1985b
cf. simple triangle Winfrey et al. 1987
cf. triangle curved margin ends Doyle and Riedel 1985b
narrow triangle straight inbase Doyle et al. 1974
triangle sigmoid rough Ramsey et al. 1976
cf. wide triangle Dunsworth et al. 1975
cf. straight triangle keeled edges Ramsey et al. 1976
cf. wide crescent Doyle et al. 1978
Undescribed triangular flanged tooth:
triangle chisel-top new subtype
Figure 48
a9/b1/c1/d1/e1/f4a±8/g1/h1,5/i5,9,10/j2,5,9,10/k1,8/m0.09-0.5/n≤2/p0/q2,9/r1/s4/t3/z0
Characters: Tooth asymmetric and rounded, approximately triangular; with a chisel-top apex and an inflated wedge-shaped to irregular base; height/width ≤2. Margins variable; in one view: one margin apically convex and other margin approximately straight; in another view both margins convex to sigmoid. Inline narrow cone-shaped in one view, in other view funnel-shaped; shape generally similar to outline. Apical region shadowed and may have striations.
Remarks: This tooth is distinctive with its odd chisel-shaped apex, inflated wedge-shaped base, and prominent inline.
Occurrence: 3 specimens, 1 fragment, 5 questionable specimens; offshore wells Shell-Anglo Apollo J-14, Cygnet J-100, Prometheus H-68, and Zeus D-14; Bulbous Base ichthyolith Zone; Miocene and lower Pliocene, possibly upper Oligocene.
cf. triangle notched corner
Doyle et al. 1974, p. 847
Figure 49
a9/b5+8/c(9,13)+19/d(9,13)+19/e1/f (9,10)+12+(14,15)/g7/h1,5/i3,4/j6,10/k5,7/m0.85-0.9/n>2/p0/q0,2,6/r0,1,4/s1/t4/z0,7,11
Characters: Tooth triangular with prominent flanged occlusal crest margins; both basal margins modified by shallow simple angle that curves inwards, otherwise one margin convex and other concave; inline low arc or narrow (not near outline); with long (greater than three-quarters tooth height) striations between inline and outline, some may radiate laterally; may have apical and lateral shadow; elliptical and acute laterally in cross-section; apex rounded (not sharp or blunt); height to width ratio >2:1. Tooth base slightly flared and in cross-section (including view of each simple angled margin) looks puckered-lip-like; transverse line curved over inline and complex at margins.
Remarks: The Shell-Anglo specimen mainly differs from triangle notched corner Doyle et al. 1974 by having one convex and one concave margin (instead of both straight). Triangle notched corner differs from beveled triangle high inline Doyle et al. 1978 by having striations between the inline and outline and by not having a high inline that has a similar shape to the outline. Triangle notched corner is known to range from the lower Eocene to approximately the Oligocene/Miocene boundary (Doyle and Riedel 1979a, p. 152).
Occurrence: 1 specimen; offshore well Shell-Anglo Apollo J-14; Bulbous Base ichthyolith Zone; middle to upper Miocene.
beveled triangle high inline
Doyle et al. 1978, p. 749
Figure 50
a9/b5+8/c13+19/d13+19/e1/f1,4a/g7/h1,5/i2/j2/k7,8±12/m0/n0,>2/p0,>2/q1,2/r1,4/s0/t4/z0
Remarks: This Tofino Basin tooth is triangular with prominent flanged occlusal crest margins. Both basal margins are modified by a shallow simple angle (otherwise margins are approximately straight). The inline is narrow (not near the outline), a similar shape to the outline but attenuate apically and slightly widens basally with lateral shadow. The tooth is elliptical, acute laterally in cross-section, and has a height to width ratio >2:1. The apex is missing. The tooth base is slightly flared and in cross-section (including view of each simple angled margin) looks puckered-lip-like. The transverse line is complexly curved.
The Shell-Anglo specimen differs by potentially having a higher height to width ratio that is >2.1. Beveled triangle high inline is known to range from the Lower Paleocene through the lower Eocene and one specimen in the Campanian (Doyle and Riedel 1979a, p. 156).
Occurrence: 1 specimen; offshore well Shell-Anglo Pluto I-87; Oligocene.
cf. triangle bowed inline
Ramsey et al. 1976, p. 130;
emend.
Doyle and Riedel 1979a, p. 115
Figure 51
a9/b5+8/c±13+19/d±13+19/e1/f4a+b/g7/h0,1,5/i1,4,5,10/j1,4,5,10/k3/m0.2-0.4/n1.4-2.0/ p0/q0,2/r0,1/s3/t4/z0,2
Characters: Tooth triangular and moderately robust; taller than wide (ratio: 1.4-2.0:1); inflated basally and centrally; inline similar to outline, moderately high, widens basally and apically, and centrally is bowed inwards; prominent apical and lateral shadow; margins sinuous and curve inwards apically and basally; asymmetric-elliptical and acute laterally in cross-section; occlusal crest flange moderately thin and basally and apically thins; apex broadly blunt; inline and tooth base break approximately straight across.
Remarks: The Hesquiat Peninsula specimens differ from triangle bowed inline by having an occlusal crest flange or ridge that slightly curves-in basally, and the teeth are asymmetric-elliptical and acute laterally in cross-section. Having a broadly blunt apex and being inflated centrally and basally makes these specimens distinctive and different from triangle modified margin ends Doyle and Riedel 1985b.
Occurrence: 2 specimens; Hesquiat Peninsula; upper Eocene.
triangle modified margin ends Doyle and Riedel 1985b. p. 358
Figure 52
a9/b5+8/c13+19/d13+19/e1/f4a+b/g7/h0,1,5/i2,4/j2,4/k3/m0.4-0.7/n1.2-2.0/ p0/q0,6,7/r0,3/s1,3/t4/z4
Remarks: Tofino Basin teeth are triangular, cone-like (inflated basally), and with one or both margins concave or straight and slightly basally convex. The crown margins have a flanged occlusal crest, which terminates equally at a point basally. The inline and transverse line are shallowly curved. The tooth is elliptical and acute laterally in cross-section with a height to width ratio 1.2-2.0:1. The apical region is shadowed and the apex rounded (not sharp or blunt). The inline is one-half to two-thirds the tooth height, bowed-in, and approximately a similar shape to the outline.
Triangle modified margin ends differs from simple triangle Winfrey et al. 1987 by having 1) a higher inline that is bowed-in and not arcuate; 2) slightly curved and pointed margins ends; and 3) a shallowly curved inline/transverse line. It mainly differs from triangle curved margin ends Doyle and Riedel 1985b by not having distinct curved margin ends and a lower inline. Triangle modified margin ends occurs in the lower Paleocene (Doyle and Riedel 1985b, p. 358).
Occurrence: 3 specimens; offshore wells Shell-Anglo Apollo J-14, Zeus D-14, and Zeus I-65; deposited in a turbidite, or near and unconformable surface in Miocene strata; probably reworked from older Cenozoic strata.
cf. simple triangle
Winfrey et al. 1987, p. 459
Figure 53
a9/b5+8/c±13+19/d±13+19/e1/f4a+b/g7/h0,1,5/i2,4/j2,4/k5/m0.65-0.85/n<2/ p0/q0,2,6,7/r0,1/s1,3,4/t2,4/z2,4/cc1/dd1/ee1/ff0/gg4/hh1.0-1.5/jj2/kk2/mm1/nn1
Characters: Tooth triangular to almost conical; inflated basally; with a thin flanged occlusal crest and straight across transverse line; margins straight to slightly convex basally; inline arc-shaped and about one-third (or <one-half) tooth height; cross-section circular to slightly acute laterally; apex acute to rounded and with shadow; height to width ratio 1-2:1.
Remarks: The Shell-Anglo specimens differ from simple triangle by having a straight across transverse line in most specimens, an inflated cap base, and a greater height to width ratio in some specimens. Simple triangle mainly differs from triangle curved margin ends Doyle and Riedel 1985b by having a shorter inline that is arc-shaped and not having distinctly curved margin ends. The earliest occurrence of simple triangle is in Cretaceous or older strata (Winfrey et al. 1987).
Occurrence: 6 specimens; offshore wells Shell-Anglo Cygnet J-100, Pluto I-87, Prometheus H-68, and Zeus D-14; long ranging, Oligocene to Pliocene.
cf. triangle curved margin ends Doyle and Riedel 1985b,
p. 359
Figure 54
a9/b5+8/c13+19/d13+19/e1/f4a+b/g7/h0,1,5/i4/j4/k0/m0/n1-1.5/p0/q0,7,8/r0,3,4/s1/t2,4/ z4,7,11/cc1/dd1/ee1/ff1/gg3+4/hh2-3/jj3/kk4/mm1.5-3.0/nn0.2-0.5
Characters: Tooth triangular with flanged occlusal crest margins that basally curve to a point at about same level; and a curved, complexly curved, or flexed transverse line. Tooth cap shadowed; elliptical and acute laterally in cross-section; height to width ratio 1.0-1.5:1; apex rounded (not sharp or blunt); outline smooth; inline absent or not close to outline. Tooth base with parallel sided inline that terminates before transverse line; one margin concave, other margin convex; outline stippled, weakly striated and/or basally irregularly striated; without occlusal crest; circular in cross-section; widens basally.
Remarks: The Shell-Anglo well specimens differ from triangle curved margin ends Doyle and Riedel 1985b by not having an inline in the tooth cap and by having a distinctly curved tooth base with a parallel-sided inline or inline not close to the outline. Triangle curved margin ends occurs in the upper Paleocene through lower Eocene (Doyle and Riedel 1985b.). A similar undescribed form found in the lower Eocene is illustrated in Plate 4, Figure 9 (Doyle et al. 1974). Other similar subtypes triangle pointed end margins Doyle et al. 1974 and triangle transverse line across Doyle et al. 1974 differ by having a tooth cap inline that extends into the upper tooth half. Triangle curved margin ends differs from narrow curved triangle Doyle et al. 1974 and curved triangle parallel sided inline new subtype and curved triangle wide inline new subtype by having a tooth cap flanged occlusal crest.
Occurrence: 5 specimens; offshore wells Shell-Anglo Apollo J-14, Pluto I-87 and Zeus D-14; cf. Triangle Curved Margin Ends interval; lower and middle Miocene, ?Eocene-?Paleocene.
narrow triangle straight inbase
Doyle et al. 1974, p. 846;
Doyle and Riedel 1979a, p. 87
Figure 55
a9/b5+8/c13+19/d19/e1/f4a+b/g7/h0,4/i4/j2,6/k8,14/m0.3-0.6/n>1.5/p0/q0,3,4/r0,1/s1/t4/z10,11
Remarks: Tofino Basin teeth are triangular, taller than wide (height to width ratio >1.5), symmetric-elliptical and acute laterally in cross-section, and basally and centrally inflated. The transverse line is flexed (centrally straight across and above margin ends, flexed at margins). Margins have a flanged occlusal crest of variable lengths (not equal in length) that are slightly basally convex or straight. The inline is similar to the outline, without canals, and high up in the tooth but not to the outline apex. The inline apex may be acuminate. The inline slightly widens basally but is not close to the outline. The crown apex is rounded (neither sharp nor blunt) and may have apical and lateral shadow.
The Tofino Basin specimens differ slightly from narrow triangle straight inbase by having one margin with slight convex basal curvature. The flexed transverse line is illustrated but not described in Doyle et al. 1974. Narrow triangle straight inbase differs from wide triangle straight inbase Doyle et al. 1974 by having a height to width ratio (from outline apex to inline base highest level) > 1.5:1. Narrow triangle straight inbase mainly differs from narrow triangle double flex Gupta 1991 by not having equal length flexed margins that terminate slightly below the inline base. Narrow triangle straight inbase occurs in the late Paleocene through Quaternary (Doyle and Riedel 1979a, p. 86).
Occurrence: 3 specimens, 1 questionable specimen; Hesquiat Peninsula, Nootka Island, and offshore well Shell-Anglo Zeus D-14; upper Eocene to lower; reworked in lower to middle Miocene.
triangle sigmoid rough
Ramsey et al. 1976, p. 132
Figure 56
a9/b±5+8/c19/d19/e1/f(4a+b)+9+12+14/g (4,6)+7/h0/i9/j10/k7+8/m0/n>2/p0/q0,2,10/ r0,1/s1,2/t4/z2
Remarks: These BC offshore teeth are triangular, sigmoidal, taller than wide (height to width ratio >2:1), and asymmetric and acute laterally in cross-section. The tooth base is slightly flared and basally inflated more on one side than the other. The tooth crown has a thin sigmoidal flanged occlusal crest, one margin sigmoid-shaped, other margin reverse sigmoid, a base with a straight across transverse line (or breaks irregularly), and shadow that darkens most of the tooth interior. The inline is narrow and parallel sided with common striations in the apical region, which do not extend to the outline apex. The tooth apex is approximately sharp to slightly rounded. The tooth outline has common vertical ridges or lines (some basally bifurcating) on the basal one-half of the labial face.
The Shell-Anglo specimens differ from triangle sigmoid rough by having outline basal vertical ridges/lines and possibly having a parallel-sided inline. Triangle sigmoid rough occurs in the Upper Jurassic through Eocene and is rare in the Oligocene (Doyle and Riedel 1979a, p. 142).
Occurrence: 1 specimen, 1 questionable fragment; offshore wells Shell-Anglo Pluto I-87 and Murrelet K-15; Oligocene/upper Eocene.
cf. wide triangle
Dunsworth et al. 1975, p. 857;
Doyle and Riedel 1979a, p. 78-79
Figure 57
a9/b5+8±(10,12)/c19/d19/e1/f(4a±b)±8±22/g3+7+8/h0,1,3,5/i3,4/j3,4/k5,8/m<0.3/n0.4-1.4/ p0/q0,6,7/r0,1/s3/t4/z0,4,5,7,8,9,10,11
Characters: Tooth triangular and almost opaque; about as tall as wide or slightly taller; with flanged occlusal crest; margins both evenly convex or basally convex and may terminate at different levels; inline base or transverse line an inverted U-shape (convex-up) and may be beveled; inline an arc or similar shape to outline, high in tooth; area between inline and outline very shadowed and may contain striations; apex rounded; elliptical and acute laterally in cross-section; outline pitted texture or with irregular short striations.
Remarks: The Tofino Basin specimens differ from wide triangle by having a textured outline and some specimens with a height to width ratio >1. Wide triangle ranges from the lower Eocene through lower Miocene with rare specimens in the Paleocene, upper Miocene, and Pliocene (Doyle and Riedel 1979a, p. 78).
Occurrence: 5 specimens; Hesquiat Peninsula, Nootka Island, and offshore wells Shell-Anglo Cygnet J-100 and Zeus D-14; long ranging, Oligocene through Pliocene.
cf. straight triangle keeled edges
Ramsey et al. 1976, p. 131
Figure 58
a9/b8/c13+19/d13+19/e1/f(4a+b)+8,(9+13+22)/g7/h0/i3,4/j2/k8/m0.8/n>1.5/p0/q10/r1/s3/t4/z0
Characters: Tooth triangular; with flanged occlusal crest; one margin convex; other margin approximately straight; apex blunt; base breaks irregularly; inline similar shape to outline; striations between inline and outline; height to width ratio >1.5:1; elliptical and acute laterally in cross-section.
Remarks: The Shell-Anglo specimens are almost opaque where inline, striations, and shadow darken the interior. This specimen differs from straight triangle keeled edges by having one convex margin and a height to width ratio greater than 1.5:1. Straight triangle keeled edges is known to occur from Upper Jurassic through Miocene (Doyle and Riedel 1979a, p. 118).
Occurrence: 2 specimens; offshore wells Shell-Anglo Cygnet J-100 and Zeus I-65; Oligocene and Pliocene.
cf. wide crescent
Doyle et al. 1978, p. 749
Figure 59
a9/b8±(10,12)/c19/d19/e1/f4a+b/g3+7/h3/i3,4/j2,3/k8/m0.15-0.25/n≤1/p0/q9/r1/s3/t4/z0
Characters: Tooth triangular; short (width ≥ height); apex blunt or rounded; one margin convex or basally convex and other margin straight to slightly convex; inline similar to outline; possible second similar-shaped inline below primary inline; prominent lateral shadow thins basally on margin-one; with occlusal crest ridge; symmetric-elliptical and acute laterally in cross-section; basally inflated; basal inline breaks irregularly; outline surface weakly stippled or textured.
Remarks: The Hesquiat Peninsula specimen differs from wide crescent by not having basal margins at a similar level and by having a base that breaks irregularly. Wide crescent ranges from the Campanian to lower Paleocene with rare specimens in the lower and middle Eocene and upper Miocene (Doyle and Riedel 1979a, p. 140).
Occurrence: 1 specimen; Leclair Point, Hesquiat Peninsula; upper Eocene/lower Oligocene.
Undescribed triangular flanged tooth, Form A
Figure 60
a9/b7+8/c19/d19/e1/f0/g5+7/h1,5/i2/j2/k1/m0.33/n2.9/p0/q0,6,9/r0,1/s1/t4/z0,11
Remarks: This tooth has flanged occlusal crest/margins, one mesial line/ridge about two-thirds the height of the tooth from the base, straight margins, and a height to width of approximately 3:1.
Occurrence: 1 specimen; offshore well Shell-Anglo Pluto I-87; Oligocene.
