fossilsonwheels Posted February 6, 2019 Share Posted February 6, 2019 Our last post ended with goblin sharks and the next era up in the presentation is one of my favorites. We get to the large sharks of the Cretaceous. This is also where the adaptations get more specific and where the science gets more heavy duty for the kids such as discussing regional endothermy. I am a firm believer than you do not "dumb down" complicated science to elementary students. You simplify and explain, you do not dumb it down. First up are the giant crushing sharks, Ptychodus. We present both P. mortoni and p. whipplei though most of the discussion is about mortoni. The kids will learn that there were at least 22 species of Ptychodus sharks, they are Hybodontid sharks and they were found in many locations around the world. They were plentiful in the Western Interior Seaway. They were large, probably very slow swimming bottom dwelling invertebrate eating specialists. We imagine them as looking similar to giant nurse sharks with features of the hybodonts. The focus is on those teeth and we have quite a few to show the kids. We explain how the separate teeth formed a plate like dentition for crushing shells. Next up is one of my favorite sharks, Cretoxyrhina mantelli. The Ginsu Shark gives us the rare chance to really described a prehistoric shark without theorizing much. The fossil record has been generous and this is a very well studied shark. We will explain to the kids that these were large sharks, up to 26 feet, and they looked very similar to modern Great Whites in general appearance. Despite being smaller than some of the monster marine reptiles, they were an apex predator. The key adaptation is the regional endothermy. For kids this goes like this... They had red muscles closer to the body axis and specialized blood vessels that allow for heat exchange. This means they were in a sense warm-blooded and this is a trait seen in modern sharks like Threshers, Makos and White Sharks. They could tolerate colder water than other species and were probably extremely fast sharks. I think the kids will get this concept and they will think this was one cool, though also kinda warm, shark lol At some point, I would love to add Cardabiodon to the program but have not seen around for sale so I assume they are rare and likely expensive. Anyway, the fossils for the program. Pic 1 One of the Ptychodus mortoni teeth we have from the Niobrara Chalk in Kansas. We have six and several are partial but put them all together in a Riker mount and they look pretty good. Pic 2 Ptychodus whipplei teeth from Kamp Ranch formation. We have a small assortment of these teeth and use them in the lab and as giveaways too. Pic 3 Cretoxyrhina mantelli from the Niobrara Chalk. Not the biggest tooth out there but one that I am very thankful to have. I will add more of these as we go along mostly because I love this species !! 2 Link to comment Share on other sites More sharing options...
ynot Posted February 6, 2019 Share Posted February 6, 2019 The whole program sound like a very interesting event. (Just don't forget the Heterodontus.) Kids should love it. Darwin said: " Man sprang from monkeys." Will Rogers said: " Some of them didn't spring far enough." My Fossil collection - My Mineral collection My favorite thread on TFF. Link to comment Share on other sites More sharing options...
Macrophyseter Posted February 7, 2019 Share Posted February 7, 2019 Best thing about this part is how they're potentially so much material you could work with on these extensively-studied sharks. The kids are surely going to have their hands full on this one Also, I think that it's still okay to include Cardabiodon into the program even if you don't have any fossil representation for it. Although we might not have too much knowledge on the genus (as we only have fossil evidence regarding its dentition, ontogenetics, and exoskeleton), Cardabiodon's a pretty cool shark that like Cretoxyrhina has its unique quirks. You could always use scientific papers as a substitute. In an age group that popularizes "cool=favorite", kids are probably going to have Cretoxyrhina and Cardabiodon as their Mesozoic favorites. If you're a fossil nut from Palos Verdes, San Pedro, Redondo Beach, or Torrance, feel free to shoot me a PM! Link to comment Share on other sites More sharing options...
fossilsonwheels Posted February 7, 2019 Author Share Posted February 7, 2019 2 hours ago, ynot said: The whole program sound like a very interesting event. (Just don't forget the Heterodontus.) Kids should love it. We will work Heterodontus in at some point for sure. Link to comment Share on other sites More sharing options...
fossilsonwheels Posted February 7, 2019 Author Share Posted February 7, 2019 28 minutes ago, Macrophyseter said: Best thing about this part is how they're potentially so much material you could work with on these extensively-studied sharks. The kids are surely going to have their hands full on this one Also, I think that it's still okay to include Cardabiodon into the program even if you don't have any fossil representation for it. Although we might not have too much knowledge on the genus (as we only have fossil evidence regarding its dentition, ontogenetics, and exoskeleton), Cardabiodon's a pretty cool shark that like Cretoxyrhina has its unique quirks. You could always use scientific papers as a substitute. In an age group that popularizes "cool=favorite", kids are probably going to have Cretoxyrhina and Cardabiodon as their Mesozoic favorites. We will work it in at some point. I think once we get a few programs under our belt, we will know where we can fit additional species in. It is high on the list of species to include for sure. I am sure we can also add a tooth at some point. I am pretty optimistic about being able to find things if we are patient. I agree. Kids will dig Cretoxyrhina and Cardabiodon when we work it in. Link to comment Share on other sites More sharing options...
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