Figure 1. Diversity of fossil ground sharks (aka carcharhiniforms) from the Florida fossil record.
Figure 1. Diversity of fossil ground sharks (aka carcharhiniforms) from the Florida fossil record.

SOLOMONS, Md. – Fossil collecting is a popular hobby, both in Maryland and Florida, especially when it comes to finding shark teeth. In fact, Florida has even been referred to as the “shark tooth capitol of the world.” And yet, there has actually been very little published research on the fossil record of sharks and rays from Florida. This new study, written by Calvert Marine Museum Paleontologist Dr. Victor Perez, documents all known fossil sharks and rays from Florida, based on specimens curated at the Florida Museum in Gainesville, Florida.

The study reports 70 different species of sharks and rays that inhabited the Florida platform from 45 million years ago to 10,000 years ago. Among these, 20 species had never been reported from the Florida fossil record. The Florida Museum has a huge collection, with over 100,000 fossils of sharks and rays from the state. Many of these fossils were donated by the amateur collectors that frequently seek out fossils.

Despite the large sample size and numerous new records, the study identified gaps in sampling where additional species are likely to be found. In particular, older fossils from the Eocene and Oligocene epochs are poorly documented from Florida, as well as smaller specimens that often go unnoticed. This new study will be a great resource to help collectors recognize if they have something new.

The study also documented an interesting transition in the dominant group of sharks, from mackerel sharks (aka lamniforms) to ground sharks (aka carcharhiniforms), which corresponded with a change in global climate. Around 34 million years ago, Earth experienced a global cooling event known as the Eocene-Oligocene transition. This climatic event contributed to widespread extinctions among mackerel sharks, which allowed the ground sharks to take over.

Ground sharks are still the dominant group of sharks in nearshore environments today, including many popular species such as bull sharks, tiger sharks, and hammerhead sharks. Many of these species have specialized cutting teeth that allow them to feed on a wide variety of prey. This likely gave them an advantage over many of the mackerel sharks, which had long, narrow teeth adapted to feed on smaller, fasting moving prey.

The paper is published in the journal Paleobiology and is completely free to access:

Explore how the prehistoric past, natural environments, and maritime heritage come to life and tell a unique story of the Chesapeake Bay. The Calvert Marine Museum is open daily from 10 a.m. to 5 p.m.  Admission is $9.00 for adults; $7.00 for seniors, military with valid I.D, AAA and AARP members; $4.00 for children ages 5 – 12; children under 5 and museum members are admitted free. For more information about the museum, upcoming events, or membership, visit the website at or call 410-326-2042. Follow us on Facebook, Instagram, and Twitter.

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