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Week 7 Power Poll: Marine Tetrapods

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You gon’ learn today.

Marine tetrapods are the true rulers of the sea.

Hey-ooo. Let me tell you, there is something so sweet about writing an article the week after Rutgers’ first Big Ten WIN of the Chris Ash era! (Sorry Illinois, twas nothing personal). Overall, this past weekend was very interesting and I think revealed some true colors for many teams in this conference. My thoughts include, but are not limited to: What on earth, Nebraska?; Go sit in the corner Illinois; If penalties were raindrops, Michigan would drown; You failed us all, Indiana; Wait, who picked Michigan State to be good this year?; Cats > Turtles; etc…

Anyway, the best part about any game week is the following power poll. My Power Poll, as always, is an educational one. I present to you the models of my future PhD project, Marine Tetrapods! A tetrapod is a four footed vertebrate, derived from the earliest vertebrates (fish) to develop limbs and walk on land. Marine or aquatic tetrapods secondarily recolonized aquatic environments meaning that all the animals below have terrestrial ancestors with four limbs. Some are more aquatically adapted than others.

These animals are great models for studying macroevolutionary changes (evolution across long timescales) because they demonstrate completely different groups (mammals and reptiles) transitioning to aquatic environments. Marine/aquatic tetrapods exhibit convergence which is when the same features independently evolve in distantly related lineages— Like how a dolphin has a dorsal fin just like a shark (among other convergent features). It’s time for you to meet some marine tetrapods and which one your team is!

1) Ohio State: Killer Whale

Paul Nicklen

Compared to the killer prehistoric marine tetrapods on this list, people probably don’t think of the orca as a super powerful marine tetrapod, but the truth is these animals are deadly killers because of their social structure. These “wolves of the sea” hunt in pods and can actually carry out coordinated attacks on blue whales, the biggest animal on Earth. They are the largest member of the dolphin family and often kill and eat their smaller, less powerful relatives-- much like how Ohio State has decimated four lesser Big Ten teams this year.

2) Penn State: Mosasaurus

The size and power of this animal was annoyingly over-exaggerated in the movie Jurassic World, with this over-exaggeration of power mirroring Penn State fans during… always. However, there is no doubt that in its factual state it is still one of the most formidable ocean predators. Mosasaurs were huge aquatic lizards of the Cretaceous Period. And yes, they were actual lizards likely related to snakes (fitting) and monitor lizards (Komodo dragons and friends). With a potential maximum length of 56 feet, it was one of the biggest marine predators in existence. With their kinetic jaws that could unhinge like a snake’s, they likely swallowed their prey whole. This is pretty much what Penn State did to most of its opponents this year.

3) Wisconsin: Basilosaurus

Despite the name “saurus” at the end of this animal’s name, this is a mammal, an early whale to be exact of the Late Eocene (30-40 million years ago). Silly naming rules in biology make it so its name stays inaccurate and remaining very out of place among its relatives’ scientific names -- Much like the way Wisconsin stands far out compared to its Big Ten West peers. Like Wisconsin, this animal is NOT to be trifled with. This leviathan had a long serpentine body, very different from modern whales, which reached lengths of 70 feet long and was certainly an apex predator of the time.

4) Michigan State: Kronosaurus

NGM Art

This animal belonged to a group called Pliosaurs which were basically big toothy heads with flippers. It likely reached lengths of over 30 feetand is named after the leader of the Greek Titans, Cronus. This is a fitting marine tetrapod for the Spartans given the Greek origin for its name as well as the fact that this animal would have virtually no problem if it encountered any marine tetrapod below this point and potentially some above...

5) Michigan: Blue Whale

This is the biggest animal that has ever existed on this planet even when looking through the fossil record. Reaching up to 98 feet and 200 tons it is BIG. Big and Blue. Which is all it really have going for it, just like Michigan. Sure, at full size the Blue Whale has only two living natural predators, killer whales and humans, but with no real defenses except for its size, it would not fare well against any of the prehistoric leviathans which separate it from #1 on this list. Fun fact: Cetaceans (baleen whales and toothed whales [dolphins]) is actually a sub-group nested in artiodactyla—hoofed animals. Uh-huh. Whales descended from hoofed ancestors and their closest living relatives are hippos and are not too distantly related to cows, deer, and pigs.

6) Iowa: Elasmosaurus

Elasmosaurus is a member of the plesiosaur family, which includes other long-necked, four flippered marine tetrapods. The family to which Elasmosaurus belongs to, however, within plesiosaurs, had excelptionally elongate necks. This one in particular was one of the larger ones, reaching lengths around 30 feet. In terms of its association with Iowa, Elasmosaurus had a small, non-kinetic skull which would have limited the food they could eat and it definitely couldn’t handle big prey—- Iowa.

7) Northwestern: Leopard Seal

Leopard seals are the second largest Antarctic seal species. This is a powerful animal as far as living marine tetrapods go and can reach lengths of up to 13 feet. Unfortunately, even though it certainly has merit as a predator, once you start to stack it up against marine tetrapods of the fossil record it stands no chance. Its only natural predator is the killer whale, but they don’t interact much. Leopard seals are very solitary animals. Kind of like how Northwestern stands by itself as the only private institution in the Big Ten. It’s also called the Leopard of the Sea. Leopards are cats, so…. Wildcats (even though seals share a terrestrial common ancestor with bears, canines, and raccoons).

8) Purdue: Rodhocetus

Rodhocetus is a transitional whale species where it exhibits numerous characteristics of terrestrial life, but clearly has aquatic features. However, it’s just not yet at the level of being a true whale which have much more size and power and are nested earlier in this poll. But! It is getting there. Purdue seems to be transitioning to a more powerful state for sure.

Wow, look at the spread of our votes.

9) Indiana: Metriorhynchus

Metriorhynchus [Met-tree-or-ink-us], meaning “moderate snout” was a Jurassic marine crocodyliform. Moderately good team just about sums up Indiana... I think... that vote spread though... Anyway, this predator, approximately the size of a modern day crocodile, was probably effective at hunting fish, pterosaurs, ammonites, and scavenging larger animals. However, it lost the bony osteoderms which modern crocodiles have in favor of a more aquatically adapted smooth and streamlined body. Because of this, it had little protection aside from evasion and was likely preyed upon by larger marine tetrapods of the Jurassic.

10) Minnesota: Stenopterygius

Todd Marshall

Stenopterygius [Sten-op-ter-ridge-ee-us] is a very classically shaped ichthyosaur, which were highly derived (very different from ancestral form), fish-shaped reptiles. Yes, these are reptiles if you can believe it. They transitioned to aquatic environments the earliest of all the animals on this list in the Early Triassic about 250 million years ago. While this Ichthyosaur may be “classic” it just doesn’t live up to what other ichthyosaurs were—huge leviathans, including the biggest known marine reptile, shonisaurus. Perhaps Minnesota will be a big Ichthyosaur one day.

11) Maryland: Archelon

Archelon was the biggest sea turtle that ever lived and is related to the modern day leatherback sea turtle. Its bony/leathery carapace probably protected it from some larger predators and its mere size likely intimidated smaller animals, but still it was just a turtle. Having lived in the Cretaceous it was likely hunted by mosasaurs and pliosaurs. And yes, Maryland fans, I made you some type of turtle related thing because I’m unoriginal, okay?

12) Nebraska: Manatee

Manatees are in the family Sirenia which also includes the now extinct Steller’s sea cow and dugong. These fully aquatic tetrapods are literally big water cows. They mostly spend their time swimming at around 3 mph and their only defense is their girth. Sirenians are closely related to elephants and hyraxes. They actually have few natural predators in the wild aside from humans, but if they were to interact with many the animals above on this list… things would not bode well for it. And they certainly did not for the Huskers on Saturday. Oh the “huge manatee,” Nebraska.

13) Rutgers: Polar Bear

This is an animal that when looking at the rest of this list may seem that it does not belong, but a Polar Bear is, no matter what anyone says, a marine tetrapod because of its ecology and behavior— relying on the marine environment. Even though it doesn’t stand a chance against any of the heavyweights at the top of this poll, it can still pose a threat to some of the smaller marine tetrapods on the list. (Or, at least it did before climate change happened where it was thrust into a formidable, changing, and unforgiving environment).

14) Illinois: Penguin

The rope represents many things for Illinois...

Didn’t even give a specific species. Even the largest penguin is a marine tetrapod that poses zero threat to any marine tetrapod on this list (and penguins got pretty big in the fossil record). As a bird, this is actually the only dinosaur on this entire list. Very few dinosaurs transitioned to aquatic environments and penguins and some other seabirds are the few. One could make a case for Spinosaurs as well—but that is certainly NOT Illinois.

Thanks for reading. I’ll be happy to engage with you guys in the comments.

Also, check out my poll below! I included exactly 7 marine mammals and 7 marine reptiles in this Power Poll. I’m curious for outreach purposes which ones you think are cooler.

Poll

Which type of Marine Tetrapods do you favor?

This poll is closed

  • 67%
    Mammals
    (207 votes)
  • 32%
    Reptiles
    (98 votes)
305 votes total Vote Now