FOSSIL Features: Sinking Our Teeth into Dinosaur Dentition by Joy and Isabelle Churin

Sinking Our Teeth into Dinosaur Dentition

by Joy and Isabelle Churin


A couple of months ago, I decided to introduce my 8-year-old daughter to one of my most beloved movies as a child – the 1988 animated film The Land Before Time. We had a delightful time meeting Cera (a Triceratops), Ducky (a Parasaurolophus), and Littlefoot (an Apatosaurus). It has now become one of her favorite films, and it has sparked a fascination in dinosaurs and the prehistoric world. As a teacher (and proud parent!), I was more than happy to help stoke her eager curiosity by providing books, models, illustrations, as well as exploring websites (including the incredible myFOSSIL eMuseum) alongside her. We even have plans to visit a few natural history museums this year! 

My daughter is a visual learner, and she enjoys diagrams and infographics. In our search, we discovered an infographic on dinosaur teeth by Main Street Smiles that she found particularly enriching. It visualizes the colossal scale and variety of dinosaur teeth while also providing fascinating tidbits on the dental qualities, diets, and jaws of these awe-inspiring creatures. Check it out below:

As you can see, the infographic is packed with bite-sized trivia on dinosaur teeth (with the Megalodon, Saber-Toothed Tiger, and Woolly Mammoth included for good measure). We wanted to share some more compelling dino dentistry facts that we discovered during our “excavation” on the web.


What Dinosaur Had the Largest Teeth?

The “king” of dinosaurs, Tyrannosaurus rex, holds the record for the longest tooth at 12 inches. T. rex had up to 60 thick, serrated, and conical teeth that would be replaced after breakage and damage. The colossal size and immense strength of T. rex teeth meant that the replacement process took about 2 years. In fact, all species of dinosaurs could regrow teeth at varying rates! Herbivore dinosaurs like the Triceratops, Parasaurolophus, and Apatosaurus (our friends from The Land Before Time) are believed to have been able to regrow teeth quickly because of the extensive wear and tear caused by stripping and grinding plant material. However, recent research has shown that some carnivorous dinosaur species like the Majungasaurus may have regrown new teeth roughly two to thirteen times faster than other carnivores, similar to the rate of modern day sharks (every two months)!



What Prehistoric Creature Had the Greatest Bite Force?

The Tyrannosaurus rex had the most powerful bite out of any terrestrial animal. Incredible technology has enabled paleontologists to determine the approximate bite force by constructing a three-dimensional digital model of the T. rex skull using anatomical knowledge of birds and crocodiles. The results were astonishing! A T. rex could bite down with the force of 12,800 pounds, about as much as an adult T. rex weighs (or an elephant). Imagine 13 grand pianos slamming down on you! However, the sea-dwelling monster known as C. megalodon puts T. rex to shame with a staggering bite force of 41,000 pounds! It could open its jaw 6 feet wide and 7 feet tall, effortlessly chomping down on prey like dolphins, whales, and other sharks.


Why Should You Embrace Your Child’s Fascination With Dinosaurs?

As a closing note, I wanted to touch upon why I am so eager to encourage my daughter to explore the fascinating field of paleontology. Here are some of the qualities that children can develop through a giddy enthusiasm for dinosaurs:


  1. Critical thinking abilities.
  2. An understanding and respect for the scientific process.
  3. Creativity and imagination as they draw these magnificent creatures of the past, and engage in pretend play.
  4. Curiosity stimulates the growing brain to be ready for learning and information retention.
  5. Conceptual fields like dinosaurs cannot be passively absorbed. This urges children to read books, ask questions, and engage in learning. Persistence and information-processing skills are cultivated through the quest for knowledge.
  6. Dinosaur and prehistoric names are challenging – so they develop verbal and writing skills!
  7. Confidence! When children unearth the answers they seek, they will feel more capable and prepared to take on more complex problems.
  8. Dinosaurs help children learn about classification. Dinosaurs have sub-categories (plant eater, meat eater, etc.), so children develop systematic thinking and organization skills.
  9. Ignites a passion for STEM fields in both girls and boys! Equality in these fields benefits the greater good.

 Thank you so much for reading! We hope you enjoyed the infographic, the fun (and terrifying) facts, and the inspiration for encouraging children to embrace their latest fascinations, especially in conceptual topics like dinosaurs and the prehistoric world.

FOSSIL Features: Penn Dixie Fossil Park with Nathan Newell

Visiting Penn Dixie Fossil Park

by @nathan-newell


My family and I vacationed at Niagara Falls last summer (2019), and whenever I go on vacation I like to snoop around Google for paleontology-related attractions. I was excited to discover that the Penn Dixie Fossil Park ( was only a 40-minute drive from Niagara on the New York side. Fortunately, I found the site a few months ahead of the trip so I had enough time to convince my wife to take a day away from the spectacular falls to grub around in the dirt. 


Penn Dixie is a nature preserve in Blasdell, NY, a few minutes south of Buffalo. It’s a Devonian site from the Moscow Formation, a former quarry that’s been dedicated to fossil hunting. The Penn Dixie website boasts of brachiopods, horn corals, crinoids, and most excitingly for me, trilobites! There are so many fossils here that they literally bulldoze a layer every once in a while to freshen the fossil piles. This seemed ridiculous to me, considering fossil hunting in the Virginias consists of me schlepping around road cuts having rare “wow” moments whenever I happen upon random trilobite pieces. And finding cephalons (heads) with eyes is even more difficult.


mFeM 61072

When we got there, a guide gave us a very interesting tour with plenty of good tips, which unfortunately, I couldn’t pay much attention to since I was in such close proximity to trilobites just waiting to be found! I got to work as soon as I could, pinballing from this pile to that, looking for the coolest trilobites possible. I didn’t see any museum-quality specimens but I did see lots of pygidiums (tails), thoraxes, and even cephalons with eyes! There were even a good deal of brachiopods and horn corals. Every once in a while, I’ll call back to my wife and kids, exclaiming how great the fossils collecting here was. This is nothing like normal fossil collecting, so don’t get spoiled! 


mFeM 60331

Meanwhile, they had just plopped down at a random spot and sifted through rubble nearby. But hey, not everybody can be a paleo-pro like me, right? After about 15 minutes of me sprinting from pile to pile, I sprang back to my wife to show her the goods. She held something up. “Is this a good one?” It was; in fact, it was much nicer than any brachiopod I have ever found. My kids had similar luck, finding some amazing specimens, many of them better than mine. Thus, I learned an important lesson: whenever I go to a fossil site now, I try to just “plop down at a random spot” for a while and see what I find before I start scurrying around.


Overall, I had great luck finding specimens that are really spectacular, at least compared to what I usually find. If you scroll through my fossil specimens from Blasdell, NY, you will see my specimens from Penn Dixie. And I was sure to give credit where due!


If mFeM 60191 turns out to be a new species or variety somehow, I’ll name it after my wife. She earned it!

FOSSIL Features: Shark Tooth Identification with Bill Heim

A quick and dirty guide to the general identification of fossil shark teeth

by @bill-heim



This will be a quick guide to the identification of most teeth down to the level of order.  Below this, at the family, genus and species level, there are many published guides both in book form and on the internet that will help in this area.  This will cover most of the larger types which are most likely to be collected.  I will omit (for space reasons) the smaller types such as Orectolobiformes (Nurse and Carpet Sharks), Heterodontiformes (Port Jackson Sharks), Pristiophorifomes (Saw Sharks), Squaliformes (Dogfish), Squatiniformes (Angel Sharks) and older, more primitive sharks such as Hybodontiformes.  Most of these omitted types are small, rare, and/or confined to specific areas or ages and thus somewhat less likely to be collected.

Note: For sharks, Order names end in ‘iformes’, Family names end in ‘idae’. Genus names often end in ‘us’ but don’t have to.  Species names vary widely. Genus and species names are italicized. Genus is capitalized, species is not.

White Tip Reef Shark

We will briefly cover the Orders of Carcharhiniformes (Grey Sharks), Hexanchiformes (6 and 7 Gill Sharks), and Lamniformes (Giant Sharks, Makos and their relatives, and Sand Tiger Sharks).  The teeth of these various animals are usually fairly large and most often collected.

The first question to ask is what age is the tooth?  Genera and species are usually confined to a certain age frame.  Knowing that age range limits the possible identifications.



When one collects a specimen, they usually focus on the enamel blade.  As this is harder and more durable than the root, it usually survives damage and wear better than the root.  However, the root often contains details that can narrow the identification down to genus and/or species level.

Details to look for on the root are:  Is there a nutritive groove in the center of the root? This would be found on Carcharhiniformes, as with the Sandbar shark, Carcharhinus (Figure 1) and some Lamniform sharks such as the Sand Tiger Sharks here illustrated by Carcharias (Figure 2) and their relatives, along with the Porbeagle Sharks.


Figure 1. Carcharhinus tooth displaying nutritive root

Figure 2. Carcharias tooth displaying nutritive root

Are there central pore(s) as with Makos, Isurus (Figure 3); and Great Whites, Carcharodon (Figure 4)?

Figure 3. Isurus tooth displaying central pore Figure 4. Carcharodon tooth displaying central pore

Are there scattered pores across the root as found in Crow Sharks, Squalicorax (Figure 5.); Giant Sharks, i.e. Carcharocles (Figure 6) and its ancestors; the Hexanchiform sharks, such as the Six Gill, Hexanchus (Figure 7); and the Seven Gill Shark, Notorynchus (Figure 8)?

Figure 5. Squalicorax tooth displaying scattered pores

Figure 6. Carcharocles tooth displaying scattered pores

Figure 7. Hexanchus tooth displaying scattered pores

Figure 8. Notorynchus tooth displaying scattered pores.

Note: the lower teeth, illustrated here, differ by the number of cusps, lower six gill teeth have more than seven cusps, upper teeth of both species have less cusps.

Other important features can be found on the shoulders of the root. Are there lateral cusplets as with the aforementioned Sand Tigers, or as seen here in Otodus (megalodon ancestor, Figure 9)?

Figure 9. Otodus tooth displaying lateral cusplets.

 Note: There is no nutritive groove in the root. 

Are there serrations on the shoulders as seen here in a tiger shark, Galeocerdo?

Figure 10. Galeocerdo tooth displaying serrated shoulders.

Note: a shallow nutritive groove is present which helps put it in the order Carcharhiniformes. 

 All these various shoulder features are easily damaged which is why it is important to have excellent quality specimens for positive identification.



Moving on to the main cusp or blade, we can further narrow down the identification.  Keep in mind that the flat side of the tooth faces the outside of the mouth (labial) while the curved, more attractive side faces the inside of the mouth (lingual). 

The first question, is it serrated or smooth edged?  There are various serrated teeth existing at different times.  In the Cretaceous, if the tooth is serrated it usually a species of Squalicorax (Figure 11), or more rarely, Pseudocorax

Figure 11. Squalicorax tooth displaying a serrated blade.

In the Palaeocene, the only serrated tooth is Palaeocarcharodon (Figure 12).

Figure 12. Palaeocarcharodon tooth displaying a serrated blade.

In later epochs, we add the various Carcharhiniformes, including the family of Hemigaleidae, such as Hemipristis (Figure 13), along with some of the aforementioned Laminformes, Carcharodon* (Great White) and Carcharocles (Giant Shark).  There are a few others, but they are rare.

Figure 13. Hemipristis tooth displaying a serrated blade.

*Note: Most fossil species of Carcharodon are not serrated.



Once you have narrowed down the order that the tooth is found in, you can then begin getting the identification down to family and then genus and species. Published guides can help you here. In addition I have been slowly publishing identification guides in the Group -Shocking Shark Teeth- which can be found here: 

You may have to dig down to older posts to find all of them. Perhaps in the future these posts can be consolidated into a single guide.

2019 Digitization and Imaging for Amateurs Workshop Landing Page

In July 2019, the FOSSIL Project hosted a digitization and imaging workshop for avocational paleontologists. This workshop focused on photography techniques and digital editing techniques for uploading and documenting personal collections online


Application page (No longer accepting applicants)

Workshop Review Blog Post

iDigBio Workshop Review Newsletter Article

Imaging and Digitization for Avocational Paleontologists Workshop myFOSSIL Group

NAPC 2019 Landing Page

The FOSSIL Project attended and supported many aspects of the North American Paleontological Convention (NAPC) in June 2019.

Technical Sessions the FOSSIL Project Supported:

Engaging Diverse Communities in Paleontology: Innovative educational initiatives that connect culture to natural history (Symposium 37) | G. Santos, S. Mills, I. Magallanes

This symposium focused on science communication initiatives that rely on novel techniques to reach untapped audiences.


Broadening horizons of broader impacts (Symposium 35) | J. Orcutt, S. Jacquet

This symposium focused on digital outreach methods and concluded with a discussion and sharing of board games produced from outreach projects.

The FOSSIL Team live tweeted this symposium, which you can find on our twitter account by clicking here.


Two to Tango: amateur-professional interactions in advancing paleontological knowledge (Symposium 32) | J. Kallmeyer, D. Meyer

This symposium focused on fostering collaborations between amateur and professional paleontologists.

The FOSSIL Team live tweeted this symposium, which you can find on our twitter account by clicking here.

Our team also collected images from the Two to Tango Symposium and put them into a Facebook album, which you can access by clicking here.


Past, Present, and Future of the FOSSIL Project (Symposium 36) | J. Bauer

This symposium focused on the research, maintenance, and practices of the FOSSIL Project.

Broken up into four thematic blocks, the goal of this session was to foster a discussion on the past, present, and future of the FOSSIL Project. Each theme had a 15 minute ‘spark’ on the content, followed by a 15 minute panel discussion, and concluded with a 15 minute audience and presenter discussion.

You can explore the presentations for each theme by clicking the titles. The talks and panel discussions are all included!

Theme 1: Building a Community of Practice in Social Paleontology

Theme 2: Community Connections

Theme 3: Accomplishments and Outcomes

Theme 4: Future and Sustainability

The FOSSIL team curated a Facebook album from the symposium, which you can access by clicking here.

Workshop Co-Hosted:

Digital Resources in Paleontology Professional Development Workshop

The goal of this workshop was to provide K-12 teachers with digital resources for their classroom and develop their repertoire of paleontology-themed lessons. 

Hosted by the FOSSIL Project and iDigBio, with many community and local partners, this full day workshop was a great success. If you are interested in learning more about the event please check out this recap written by Jen Bauer and Molly Phillips for the quarterly newsletter: Digital Resources in Paleontology Professional Development Workshop at NAPC 2019.

The FOSSIL team curated a Facebook album with images from the event, which you can access by clicking here.

FOSSIL Participant Experiences: