Description: There are three species of sand tiger from Big Brook.  Two are in the more modern genera Carcharias: C. samhammeri and C. holmdelensis.  The third is in the more archaic genera, Odontaspis.  The sand tigers found at Big Brook are divided into two main groups; the ones that possess smooth main cusps and the ones that are striated.

The most common sand tiger shark to be found is
C. samhammeri.  Except for the growth cracks, they have a smooth main cusp on the inner lingual surface.  The main cusp is long, dagger like and is curved lingually.  The rounded, pointed and diverging root lobes have a moderately deep nutrient groove.  Also the bottom of the enamel on the labial side of the tooth usually is curved around the root arch.  Lateral and posterior teeth are similar to the anterior teeth, but are shorter and have less diverging roots.  Furthermore, the main cusp in lateral and posterior teeth is smaller and curved towards the back of the jaw.  The teeth of C. samhammeri range in length from about 1 to 2 cm (about .5 to .75 in long.

The less common,
C. holmdelensis, is the only species of sand tiger that possesses a few variations in its' teeth.  The anterior teeth are very similar to C. samhammeri.  The main difference is that these teeth have fine longitudinal striations on the bottom half of the inner curved surface of the main cusp.  The upper lateral teeth have a much broader main cusp, and are curved.  The roots are more blockie and flatened.

The third genus of sand tiger shark,
O. aculeatus, has similar teeth to that of C. samhammeri.  The main cusp on these teeth is smooth and is curved lingually.  The main difference is the size of the teeth, with 7 to 12 mm (about .5 in) long being normal.  Furthermore, these teeth are marked with a second set of cusplets beside the main cusplets.  These differences can be that these teeth belong to the juvenile C. samhammeri shark.  The identification of O. aculeatus is only tentative and study is continuing.

Commonality: The teeth of C. samhammeri are a somewhat common find at Big Brook.  C. holmdelensis is uncommon and O. aculeatus is rare because of its' small and delicate nature. 

Similar fossils: The only problem in the identification of C. samhammeri teeth is that they are similar to the anterior teeth of the goblin shark.  Goblin teeth are generally two to three times larger than the sand tiger, but this is not always the true test, especially in juvenile specimens.  A very stream-worn goblin tooth may be easily mistaken for a sand tiger, which lacks the fine longitudinal striations.  The enamel margin of the teeth of the sand tiger shark is curved closely around the root arch, which is straight across the root.  The nutrient groove of the anterior teeth of the goblin shark is not as deep as that of the sand tiger shark.  The medial protrusion is also not as prominent.  C. holmdelensis might be confused with Cretodus arcuata.  The striations on the main cusp of C. holmdelensis and the lack of them on Archaelamna kopingensis are sufficient to tell the difference.  The small size of O. aculeatus and the large cusplets make this tooth distinctive.

Size: C. samhammeri ranged from 2 to 3 meters (7 to 10 feet) in length.  The others were somewhat smaller.

Notes: Apparently sand tiger sharks have changed little since the Late Cretaceous.  The probably preferred, as they do now, the deeper open waters feeding on small to medium sized fish and squid.  The sand tiger shark genus was widespread worldwide during the Cretaceous and is still alive today.
Sand Tiger Sharks
Carcharias samhammeri (Cappetta & Case)
Carcharias holmdelensis (Cappetta & Case)
Odontaspis aculeatus (Cappetta & Case)
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Carcharias samhammeri (Cappetta & Case)
Anterior tooth
a. lingual  b. labial
Carcharias holmdelensis (Cappetta & Case)
Anterior tooth
a. lingual  b. labial
Carcharias holmdelensis (Cappetta & Case)
Lateral tooth
a. lingual  b. labial
Odontaspis aculeatus (Cappetta & Case) Lateral Tooth
a. lingual  b. labial
Carcharias holmdelensis
(Cappetta & Case)
a. Anterior tooth  b. Lateral tooth
Odontaspis aculeatus (Cappetta & Case) Anterior tooth