Q 01/05

Roughly how many teeth can a shark shed over its lifetime?

A) 300+

B) 3,000+

C) 30,000+

D) 10,000+

Answer · why

C) 30,000+

The teeth sit in the gums, not the jaw, and rows move forward like a conveyor belt.

Q 02/05

How many gill slits do sharks have on each side of the body?

A) Exactly five

B) Four to six

C) Five to seven

D) Three to four

Answer · why

C) Five to seven

Sharks also have a ribless skeleton of cartilage and pectoral fins that are not fused to the head.

Q 03/05

Across how many orders are the more than 500 living shark species divided?

A) Fifteen

B) Eighteen

C) Thirteen

D) Eleven

Answer · why

C) Thirteen

Some of those orders are extinct; the ground sharks alone include the requiem sharks, catsharks and hammerheads.

Q 04/05

The oldest total-group chondrichthyans, the spiny sharks or acanthodians, appeared in which period?

A) Early Triassic

B) Late Cambrian

C) Late Jurassic

D) Early Silurian

Answer · why

D) Early Silurian

That is around 439 million years ago; shark-like scales go back even further, to the Late Ordovician.

Q 05/05

Cladoselache, an early shark, is famous for well-preserved fossils from which formation?

A) The Solnhofen limestone in Bavaria

B) The Burgess Shale in British Columbia

C) The Green River Formation in Wyoming

D) The Cleveland Shale on Lake Erie

Answer · why

D) The Cleveland Shale on Lake Erie

Oddly, no claspers have ever been found on it, unlike its close relatives.