Tofino Basin teeth with inline canals are triangular-shaped and all but one subtype (angled cone and basal canals new subtype) have a flanged occlusal crest (Figure 40.1). The branching inline canals are distinctive for this group and are in the tooth base and crown (Figure 40).
List of identified triangular teeth with inline canals:
angled cone and basal canals new subtype
centrally inflated triangle with canals new subtype
triangle one canal above Doyle et al. 1974
cf. triangle transverse line across Doyle et al. 1974
triangle transverse line across Doyle et al. 1974
flanged triangle with canals new subtype
angled cone and basal canals new subtype
Figure 41
a9/b1,5/c11,12/d20/e1,2/f1±4a+b/g1/h0,4,5/i2,3,4,9/j2,6,7,9/k1/m0/n>1.5/p0,>1.5/q0,9,10/r0,1/s1,2/t2/z0,2/cc1/dd1/ee2/ff1/gg1,4/hh0,1-4/jj2,3/kk2,4/mm0,1-3/nn0,0.3-1.0
Characters: Tooth triangular with no occlusal crest; apically inclined (angled in apical region with one concave and one convex margin); circular cross-section; may have thin transverse line separating cap and base; may be slightly stepped. Cap smooth; commonly with pointed apex and apical shadow; margins straight, or slightly concave, convex, or sigmoid; height to width ratio 1-2:1. Tooth base with prominent branching canals throughout and may extend into basal most region of cap; outline weakly stippled; height to width ratio 1-4:1; basally breaks irregularly.
Remarks: This subtype is distinct because it has branching canals, a circular cross-section, no flanged occlusal crest, and is apically curved (convex-concave).
Occurrence: 6 specimens, 7 tooth base fragments, 2 questionable tooth caps; Flores Island, Hesquiat Peninsula, and offshore wells Shell-Anglo Apollo J-14, Pluto I-87, Prometheus H-68, and Zeus D-14; Teeth with canals ichthyolith Zone; upper Eocene and Oligocene, reworked into lower and middle Miocene.
centrally inflated triangle with canals new subtype
Figure 42
a9/b5+8/c19±(11,12,13)/d19±(11,12,13)/e2/f4a+b/g7±8/h0,1,2,3,4,5/i2,3,4,5/j2,3,4,5/k8±(12,14)/m0.04-0.35/n≤2/p0/q0,3,4,5,9,10/r0,1/s1,3/t4/z10,11/cc5/dd5/ee2/ff0/gg6±8/hh0-1.3/jj2/kk2/mm0.44/nn0.3
Characters: Tooth triangular and moderately robust; with a prominently flanged occlusal crest; symmetric-elliptical and acute laterally in cross-section; inflated basally and centrally; both margins approximately straight near apex, commonly with a simple shallow convex-outward flanged margin curvature at level of inline transverse line apex; and straight below this curvature. Inline translucent to almost opaque; contains branching canals above and below transverse line; similar shape to outline but does not approach outline basally; apex approximately three quarters tooth height but not to tooth outline apex, may terminate in a thread-canal or be acute to acuminate; base breaks irregularly. Transverse line flexed; centrally above base of flanged margins where it traverses approximately straight across; near flanged margins it commonly steeply drops basally and then cuts across each flanged margin. Tooth with lateral and apical shadows between apical inline and outline; apex blunt to rounded; basal flanged margins extend below transverse line apex and variable lengths. Tooth crown above transverse line commonly taller than wide (height to width ratio≤2:1).
Remarks: The Tofino Basin specimens differ from triangle with canals Doyle et al. 1974 by having: a flexed transverse line, convex outward curvature of the flanged margin near the apex of the transverse line in many specimens, an acute to thread-like inline apex in several specimens; and an inline base that is not greater than two times the width of the transverse line (inline base commonly narrower and less basally flaring than triangle with canals). Triangle transverse line across Doyle et al. 1974 has fewer inline canals, a greater tooth crown height to width ratio (above transverse line), and has a transparent inline region. The inline of centrally inflated triangle with canals is translucent to opaque and is a similar shape to the outline.
The Tofino Basin specimens have similar margins to narrow triangle straight inbase and wide triangle straight inbase both Doyle et al. 1974 but these forms do not have inline canals (see emend. Doyle and Riedel 1979a, p. 87 and 91). Centrally inflated triangle with canals differs from flanged triangle with canals new subtype by having 1) an inline that is a similar shape to the outline and not transparent, 2) a greater number of canals that are denser, 3) a greater inflated tooth central and basal region, and 4) a transverse line.
Occurrence: 38 specimens, 1 fragment, and 11+ base fragments; Hesquiat Peninsula and offshore well Shell-Anglo Pluto I-87; Centrally Inflated Triangle With Canals ichthyolith interval; upper Eocene and Oligocene, ?middle to ?lower Eocene.
triangle one canal above
Doyle et al. 1974, p. 848;
and Doyle and Riedel 1979a
p. 193
Figure 43
a9/b5+8/c13+19/d13+19/e2/f4a±b/g7/h0/i2,4/j2,4/k1/m0/n>1<2/p0/q0/r0/s1/t4/z7,11,12/cc5/dd5/ee2/ff1/gg4+6/hh2.0-2.5/jj3,6/kk5,6/mm2.0-2.5/nn<0.3
Remarks: Tofino Basin teeth are triangular and slightly curved (convex/concave) with a complex-curved to flexed-curved transverse line and multiple branching canals that are prominent in the tooth base and one or two above the transverse line. The inline is transparent between canals. The tooth is elliptical and acute laterally in cross-section with a more prominently flanged crest on the tooth base than cap (above transverse line). The tooth cap has apical and may have lateral shadow, and the apex is rounded and neither blunt or sharp. Tooth margins are straight or basally convex. The tooth height to width ratio above the transverse line is >1<2:1. The tooth base is tall (height to width ratio 2-3:1), slightly widens basally with an irregular break, and one margin is convex or reverse sigmoid.
The Tofino Basin specimens may have one or two canals above the transverse line and have a distinctive transparent inline between the prominent branching canals. Triangle one canal above is known to range from the lower Eocene through the middle Miocene (Doyle and Riedel 1979a, p. 192).
Occurrence: 5 specimens; Flores Island and offshore well Shell-Anglo Pluto I-78; Teeth with canals ichthyolith Zone; upper Eocene and Oligocene, reworked into the lower to middle Miocene.
cf. triangle transverse line across
Doyle et al. 1974, p. 848;
emend.
Doyle and Riedel 1979a, p. 109
Figure 44
a9/b5+8/c13+19/d13+19/e2/f(4a+b)±(8,22)/g7/h0,1,5/i2,4/j2,4/k1,12/m0,0.02-0.4/n1.9-2.5/p0/q0,6,7/r0,3,4/s1,3/t4/z4,7
Remarks: These specimens differ from triangle transverse line across Doyle et al. 1974 by having a curved transverse line and flanged margins that are basally convex and curve inwards at the same level to a point. Also, 3 specimens (e.g., Figures 44.2.1, 44.3.1) have inline striations that radiate from the canal region.
The curved and flexed transverse line has been previously described and illustrated in triangle transverse line across but both these transverse lines are distinctive in the Tofino Basin specimens and therefore have been separated.
Occurrence: 4 specimens; offshore wells Shell-Anglo Pluto I-87 and Prometheus H-68; Teeth with canals ichthyolith Zone; Oligocene, reworked into the lower Miocene.
triangle transverse line across
Doyle et al. 1974, p. 848;
emend. Doyle and Riedel 1979a, p. 109
Figure 45
a9/b5+8/c19/d19/e2/f4a+b/g7/h0,1,4,5/i2/j2/k1,12/m0,0.02-0.4/n1.9-2.5/p0/q0,3,6/r0,1,3,4/s1,3/t4/z4,10,11
Remarks: Tofino Basin teeth are triangular, taller than wide (height to width ratio 1.9-2.5:1), widen basally, and elliptical and acute laterally in cross-section. The apex is rounded (not acute or blunt), and lateral shadow may be present. The inline contains branching canals that form a single thread apical canal that commonly extends into the upper two-thirds to three-quarters of the tooth crown. The region between branching canals is transparent. The transverse line is flexed and terminates about equally at both tooth margins. Crown margins are straight, both with flanged occlusal crest and may be pointed basally or break straight across.
The Shell-Anglo specimens are noted for the high (in upper crown two-thirds to three-quarters) apical thread canal and the presence of other basally branching canals. A similar subtype, triangle curved base Doyle et al. 1978 was not chosen because the branching canals do not extend beyond one half the tooth height. Triangle transverse line across occurs in the upper Paleocene through lower Miocene (Doyle and Riedel 1979a, p. 108).
Occurrence: 7 specimens; Hesquiat Peninsula and offshore wells Shell-Anglo Pluto I-87 and Zeus D-14; Teeth with canals ichthyolith Zone; Oligocene, reworked into the lower Miocene.
flanged triangle with canals new subtype
Figure 46
a9/b8/c19/d19/e2/f1,(4a ±b)/g7/h0,1,4,5/i2,3,5/j2,3,5,6/k1,8/m0.1-0.5/n>1.5/p0/q9,10/r1/s1,3/t4/z0
Characters: Tooth triangular; taller than wide (height to width ratio >1.5:1); inline consists of prominent branching canals that form a single canal apically but do not extend to outline apex; inline transparent between canals; transverse line absent; base breaks irregularly; apex neither blunt or sharp; apical and lateral shadow may be present. Tooth widens basally; flattened apically and slightly more inflated basally and centrally; elliptical and acute laterally in cross- section; margins straight or slightly curved (convex/concave) and with prominent (non-crenulated) occlusal crest lateral flanges. In profile view, tooth thin and shows convex/concave curvature.
Remarks: Flanged triangle with canals differs from triangle one canal above Doyle et al. 1974 (p. 848) by not having a transverse line and the tooth widens basally not forming a shaft-like base. Flanged triangle with canals differs from triangle with canals Doyle et al. 1974 (p. 848) by not having a transverse line within the outline, by having a transparent inline between the canals where the canals appear to float within the tooth, and the teeth generally have a greater height to width ratio.
Sixteen base fragments of either flanged triangle with canals or triangle one canal above were found in samples from the Pluto I-87 well and near the base of the Zeus D-14 Shell-Anglo well.
Occurrence: 11 specimens; Flores Island, offshore wells Shell-Anglo Pluto I-87 and Prometheus H-68, and offshore core END-76B-5; Teeth with canals ichthyolith Zone; upper Eocene and Oligocene, reworked into the lower Miocene.
