By the Tooth of the Shark
Lesson at a glance:
In this lesson, older students will gain an understanding of how to use a field guide and
will learn some of the characteristics that are used to identify sharks. Older students will
also conduct independent or group research on each shark species included in the field
guide. Younger students will benefit from simply matching the appropriate shark teeth to
the appropriate sharks.
Materials:
 Field guide sheets
 Shark vocabulary list
 Shark field guide
 Unlabeled shark teeth images
 Shark teeth teacher key
 Scissors
 Glue stick
 Zip-lock baggies
Background:
Sharks species can be identified by their range, size, color, body shape and tooth shape.
Shark teeth are a key characteristics used by scientists when identifying shark species.
Fossilized shark teeth have been especially helpful in learning about shark evolution
since a shark’s cartilaginous skeleton rarely fossilizes.
Rows of replacement teeth continually develop behind outer rows of feeding teeth.
Sharks frequently lose teeth while capturing prey. As a tooth falls out, a replacement
tooth takes its place. Individuals of some species lose as many as 30,000 teeth in a
lifetime.
In this activity, your students will be using the field guide included with this activity to
identify shark teeth that may have been found washed up on a beach. Each species of
shark has a differently shaped tooth depending on their diet.
Visit www.elasmo.com (click on “extant dentition) to see a variety of shark jaws.
Activity:
Preparation:
1. Make copies of field guide and Shark Vocabulary pages for each student or group
of students.
2. Pre-cut enough of each shark tooth (separate upper and lower teeth) for each
student or for several groups of students.
Activity:
1. Discuss what characteristics scientists use to identify shark species (see
background information).
2. Give each student or group a copy of the field guide sheets.
3. Discuss scientific vs. common names. Scientific names are used by scientists all
over the world regardless of the language they speak. Scientific names are usually
Greek or Latin and include the genus group the animal belongs to and its species.
Common names may vary worldwide or even within one region.
4. Explain to students that they will be doing research to find the range and diet of
each of the sharks included in the field guide. Students should use a variety of
resources including books and the internet.
5. Have at least one regular field guide available for students to reference.
6. Once the research portion of the activity is completed, give each student or group
a glue stick and a baggie with the pre-cut, unlabeled shark teeth.
7. Have the students match the loose teeth with the shark species on the field guide
pages.
8. On a separate piece of paper have students make a shark tooth key by gluing the
shark teeth to the paper and labeling them.
9. Encourage students to make a connection between the kinds of food each shark
eats and how their teeth might help them to catch and consume their prey.
Extensions:
1. Have students choose a different species of shark, skate or ray. Next, have then
find their diet, range and a description of the shark including their teeth (if
available).
2. Have students create a report on a species of shark that includes a drawing of the
shark and its teeth.
Shark Field Guide
Upper tooth
Lower tooth
Common name: Tiger Shark
Scientific name: Galeocerdo cuvier
Description: Tiger sharks have a torpedo shaped body. Their back is gray with dark
stripes. Their first dorsal fin is much larger than their second dorsal fin.
Length: up to 18 feet
Range:
Diet:
Upper tooth
Lower tooth
Common name: Sevengill shark
Scientific name: Notorynchus maculatus
Description: Sevengills have a long, rounded body. They are brownish to dark gray and
usually have many dark spots covering their bodies. Unlike most sharks these sharks have
seven gill slits on either side of their head rather than five. They are also unique in that
they only have one dorsal fin. The teeth in their upper jaw are shaped differently than the
teeth in their lower jaw.
Length: up to 10 feet
Range:
Diet:
Upper teeth
Lower tooth
Common name: Cookie-cutter shark
Scientific name: Isistius brasiliensis
Description: These little sharks are chocolate colored over most of their bodies with a
dark collar around their gill slits. They have no anal fin. Their eyes are green. Cookiecutter sharks feed on prey larger than themselves. Their fleshy lips help them to suck onto
their prey while they use their teeth to remove a chunk of flesh.
Length: up to 1.5 feet
Range:
Diet:
Upper tooth
Lower tooth
Common name: Soupfin shark
Scientific name: Galeorhinus zyopterus
Description: Soupfin sharks have very sleek torpedo shaped bodies. They are gray on
their backs and lighter colored on their bellies. Their snout is long and pointed. Their
second dorsal fin is smaller than their first dorsal fin.
Length: up to 8 feet
Range:
Diet:
Upper tooth
Lower tooth
Common name: White shark
Scientific name: Carcharadon carcharias
Description: White sharks can be quite robust. They are gray or brownish on their backs
and lighter gray to white on their bellies. Their snout is pointed. Their anal fin is located
directly under their second dorsal fin. The caudal fin is crescent shaped with each lobe
being roughly the same size. Their teeth are triangular and serrated.
Length: up to 21 feet
Range:
Diet:
Upper tooth
Lower tooth
Common name: Shortfin mako
Scientific name: Isurus oxyrinchus
Description: Their torpedo shaped body is grayish blue to deep blue above, white below.
The snout is sharply pointed. The caudal fin is crescent shaped with both lobes equal in
size. Mako’s are one of the fastest swimming sharks. They have fewer teeth than most
shark species. Their teeth are pointed by not serrated. Often mistaken for a white shark.
Length: up to 13 feet
Range:
Diet:
Upper tooth
Lower tooth
Common name: Leopard shark
Scientific name: Triakis semifasciata
Description: Leopard sharks are silvery gray or brown with black spots and wide black
stripes. Their dorsal fins are approximately the same size. Pectoral fins are pointed. These
sharks have tiny spiracles behind their eyes that help them to pump water over their gills
as they rest on the seafloor.
Length: up to 6.5 feet
Range:
Diet:
Upper tooth
Lower tooth
Common name: Salmon shark
Scientific name: Lamna ditropis
Description: Salmon sharks have stout, torpedo shaped bodies. They are a dark bluish
gray on their backs and white on the lower sides of their body, including their belly. Their
snout is coned shaped and very pointed. Their three pronged teeth have smooth edges.
Length: up to 10 feet
Range:
Diet:
Shark Teeth
(Teacher’s Key)
Cookie-cutter shark
Leopard shark
Salmon shark
Soupfin shark
Sevengill shark
Shortfin mako
Tiger shark
White shark
Shark Teeth
Directions:
1. Make enough copies so that each group or individual student has a set.
2. Pre-cut teeth and place each set in a baggie.