If you like paleontology and zoology etc. like and reblog this post for a a chance to win one of these packs! Each pack comes with 5 individual cards with 24 different animals/ plant designs! I will select winners using a randomizer. Good luck!
I will only be shipping out to US, CA, UK, AUS, EU, SA.
If you like paleontology and zoology etc. like and reblog this post for a a chance to win one of these packs! Each pack comes with 5 individual cards with 24 different animals/ plant designs! I will select winners using a randomizer. Good luck!
I will only be shipping out to US, CA, UK, AUS, EU, SA.
Today, we’re going back to the Carboniferous period! If you’ve been following this blog for a while, you might remember Westlothiana, a little amphibian and/or reptile* that looked a little like a lizard. As I said back then, vertebrates were only just getting started on land. They were mostly small, skittering animals. Arthropods, though, were a different case. They first arrived on land in the Silurian period, almost 60 million years before fish took their first soggy, awkward steps onto land. Arthropods were the first animals in earth’s history to fly, and had set up shop pretty firmly by the Carboniferous period.
The earth was wetter and covered in rainforests back then. There was also a lot more oxygen in the air. Insects and other arthropods have very simple respiratory systems. Air flows into their bodies through openings in their exoskeletons called spiracles, then makes its way into the air sacs and distributed accordingly. This is all I know about arthropod breathing. But, this system is much less efficient than the one seen in vertebrates. It puts a size cap on terrestrial arthropods. If they get too big, the air can’t flow through their bodies, and they can’t breathe. But, in the Carboniferous, arthropods were able to get HUGE, thanks to the increased oxygen content of the air. And Eophrynus is… not one of them.
No,Eophrynus is around an inch long (2.5cm, for you non-yanks). It’s a little arachnid from the late Carboniferous. It’s is a Trigonotarbid, an order of arachnids that lived from the late Silurian until the early Permian. They were closely-related to spiders, but slightly more archaic. They were shaped similarly, but didn’t make silk, and their front pair of limbs—called pedipalps—weren’t modified into claws or pincers. Also, there’s no evidence they used them to deliver sperm into females, which is apparently something spiders have been doing for a while.
It’s a little hard to say exactly how closely or distantly they were related. Arachnids are hard to sort phylogenetically, partially because they all share a very similar body plan. We can usually say if they’re closer to spiders or scorpions, but we haven’t quite figured out much beyond that. We have theories, sure, but it’s not quite set in stone. Well, it’s the fossil record, so, it’s… You know what I mean.
Anyway, like most arachnids, Eophrynus was a predator. It lived on the forest floor, and used its long legs to chase down other, smaller arthropods. But, of course, being a tiny arthropod, it was probably eaten by small amphibians and reptiles. Its abdomen was lined with protective spikes in an attempt to keep this from happening, but let’s be real, if something wants to eat you badly enough, it will. Look at Koalas and Eucalyptus, or Mongooses and venomous snakes. Animals are buckwild.
That’s our animal for today! I’ve talked about invertebrates a few times on this blog, but they’ve always been marine. Marine invertebrates are my favorite group of animals, and I think my bias has been a little clear here.
And, I’ll talk about giant Carboniferous insects soon, I promise. I like them, too. I just want to give the lesser-known, more mundane animals their time to shine, too.
*Mspaleoart drinking game: take a shot every time I mention how wack taxonomy is
Remember a while ago, when I talked about big Carboniferous arthropods, and then proceeded to talk about a tiny one? And then at the end, promised to talk about the big ones ‘soon’? Well, it’s finally time. This is one of my favorite insects of all time, and one that was really, really fun to draw.
Meganeura, (‘large nerve,’) was one of the biggest flying insects ever. Its wingspan ranged from 25-28 inches (65-70 centimeters). This is an insect the size of a crow, as David from the Common Descent Podcast put it. It’s a member of a clade called Meganisoptera, or griffinflies, and are closely-related to dragonflies and mayflies. Meganeura is an unusually well-preserved insect. Its name comes from the fact that several of its fossils clearly shows the veins of its wings. This is what we paleoinvertebrate enthusiasts call a Big Deal™. And look at the detail of those segments, and even the head, which is unusual for Meganisopteran fossils.
I discussed this the last time I talked about a Carboniferous arthropod, but the Carboniferous and very early Permian are the only time insects got this huge. Afterwards, they never got quite this big again. That’s likely because the Carboniferous atmosphere contained around 33% oxygen content, whereas now it’s only 21%. Arthropods have no lungs. Air flows through openings in their body called spiracles, and is then carried through their respiratory system and distributed through the body directly. The movement of the different segments of their body also helps move oxygen. They don’t inhale or exhale, and they don’t have blood as we know it. It doesn’t carry oxygen, and functions more like our lymphatic fluid.
If this sounds dumb and impractical, it’s actually way more efficient for small animals. It’s a lot less effort than active respiration. Small vertebrates are always breathing so quickly, but arthropods are just fine. The downside is, they can only get so big, since they need a certain amount of ambient oxygen or they just can’t breathe. But the Carboniferous offered exactly that, and thusly, we have monstrosities like Meganeura and its pals.
There is some controversy to this idea, though. Similarly-sized Meganisopterans lived into the Permian, when the oxygen content appears to be much closer to that of today. Scientists also point to a lack of flying vertebrates, giving insects license to party in the sky.
This was a predatory insect, if ever there was one. It ate other insects for the most part, but also ate small amphibians and reptiles if it could get ahold of them. The key phrase there is, “if it could get ahold of them.” Although its living cousins are speedy little fighter jets who can quickly zip and weave, Meganeura was a slower, more powerful ambush hunter. Its eyes were similar in shape to those of modern Hawker dragonflies, which hunt by watching the air overhead and leaping from its perch to snatch flying prey. They were adapted more for hunting in open areas, rather than the dense undergrowth so characteristic of the Carboniferous.
These wings were powerful—modern dragonflies and mayflies fly with what’s called direct flight. This means they have muscles attached directly to their wings, whereas plenty of other insects fly by flexing their bodies to indirectly move their wings. Meganeura probably moved its wings like dragonflies, and that probably allowed it to get so big while retaining its flight and lifestyle. We don’t know for sure how quickly it beat its wings, but they may have sounded something like this.
In summary, this was an insect that acted a lot like a dragonfly, only gigantic. It was a dragonfly that could eat lizards, and whose nymphs were active hunters of small fish and amphibians. This backwards world, where bugs eat fish and are the biggest terrestrial organisms, is part of what makes paleontology so exciting. Everything about Meganeura reads like a description of a sci-fi monster. This is a huge part of why I love the Paleozoic so much, too. It was the slow windup to modern conventions and ecosystems, and in the meantime, pretty much anything went. Bugs could be giant apex predators, and that was just fine.
Also, I did base its color scheme off Yanma and Yanmega, which are two of my favorite Pokemon.
Today is a special day for a couple of reasons! 1) I get to talk about the Burgess Shale again, and, 2) Today’s animal is MSPTD’s very first requested animal! So, before I get into the writeup, I want to thank @futureimagineer843 for requesting this animal! This writeup was a lot of fun and I hadn’t actually heard of this one before xe mentioned it. Also, if you ever want me to talk about a specific animal, requests are something I am absolutely open to.
Our third trip to the Burgess Shale, the famous Cambrian fossil bed from British Columbia, examines a lesser-known and lesser-understood animal named Perspicaris. Using Perspicaris, we can really put into perspective how much of a treasure trove the Burgess Shale really is. This is one of the more rare animals from the Burgess Shale, and it’s known from only 202 specimens. For comparison, we have around 50 specimens of Tyrannosaurus rex, an animal found in significantly younger rocks and one of the better-known theropod dinosaurs. It might sound ridiculous to call it rare, but those 202 fossils of Perspicaris make up only 0.38% of the Greater Phyllopod Bed, where most of the Burgess Shale fossils have been found.
We don’t know much about Perspicaris. It’s a really weird animal. It’s really similar to a common Burgess Shale animal called Canadaspis (known from 4,525 specimens and making up about 9% of the organisms found), and we can extrapolate a bit about its appearance and how it might have acted from looking at it.
Perspicaris is a tiny arthropod. It was less than an inch in length (2-3cm), and bears more than a passing resemblance to shrimp and other modern crustaceans. We’re unsure of whether or not it was an early crustacean, a basal Euarthropod (the modern groups of arthropods), or from a family outside of that group that left no descendants. It’s definitely some kind of arthropod, but getting more specific is pretty hard. That’s the problem with the Cambrian fauna, and one of the reasons it’s so fascinating. This is when just about every modern phylum evolved, so when can we say they split for sure?
It’s also hard to say what the hell it was doing with that body plan. It had big eyes on the end of stalks and limbs that could have aided swimming. But, it didn’t have any claws or enlarged biramous limbs (limbs that branch into two different segments that are usually adapted to some special purpose), so if it was swimming, how did it eat? We know Canadaspis was a bottom-feeder, but don’t have any evidence for that in Canadaspis.
This brings up the question: How do we know all these things about prehistoric animals? We use a lot of methods to figure out all this. Since the Cambrian Explosion, most animals fill different roles in a given modern ecosystem. A lot of those ecosystems have parallels between each other. Let’s use the Great Barrier Reef and an African savannah as an example. I’ll simplify it, because food webs can be really complex and can make it hard to get what I’m getting at.
At the base of both ecosystems are vegetation. In the Reef, it’s algae and kelp. In the savannah, it’s grass. Then you have the herbivores who eat those things. So, dugongs/krill, and gazelles/wildebeests. Then you have the carnivores, which eat other animals, like tiger sharks and lions. A lot of animals have a parallel animal in other ecosystems, and we can apply that same logic to prehistoric ecosystems, too. We can figure out roughly where animals fall in prehistoric food webs based on the features they share with modern animals. Canadaspis has a lot in common with modern benthic (bottom-feeding) animals, so we can say pretty confidently that it was a bottom-feeder. But what do you do when you have an animal like Perspicaris, which has a mix of traits but nothing pointing definitively in any direction? You speculate. Throw stuff at your peers and see what sticks.
Perspicaris looks a bit like tadpole shrimp. They have plenty of differences, but in broad strokes they look alike. Now, tadpole shrimp are bottom-feeders, too, but doesn’t have eyestalks like Perspicaris. Our friend here shares that with internet celebrity called the mantis shrimp, which actively hunts larger prey. But it doesn’t have claws like the mantis shrimp, so…
You see the problem. That’s why paleontologists debate a lot. A lot of media likes to sensationalize these disagreements like they’re rap beefs or something, but no they’re usually just discussions about stuff where people don’t agree. You know, like, how science works.
Also, the media tends to latch onto the more outlandish stuff. There are plenty of folks around who still correct people by saying stuff like, “Actually, they found out that T. rex was a scavenger,” even though it was a theory that people only really looked at because Jack Horner liked it, and Jack Horner is, putting it lightly, a big fucking deal. That being said, there’s a truckload of evidence against that, and most scientists brush it off because Tyrannosaurus was built like a predator. Maybe I’ll talk about that someday.
So, what’s the deal with Perspicaris? In short: ¯\_(ツ)_/¯. It’s a weird little arthropod with a really vague body shape, and it’s really hard to figure it out because it doesn’t really look much like anything around now. And the thing it does look like has specializations it lacks. They’re little mysteries in a field full of little mysteries.
i used to work at a used bookstore and there was an insect anatomy book for sale that was over $8000 im not even kidding. and i just found it at my school library. its mine for the month.
It’s page after page of the most detailed illustration on insect morphology I’ve ever seen
External anatomy only I’m afraid, but an absolutely invaluable resource nonetheless
It’s called An Atlas of Insect Morphology by Steinmann and Zombori. Looks like there are some much cheaper options now than when I last looked. When I saw it in the bookstore’s system I thought it was a pricing error but I remember looking it up and seeing one for sale that was over $10,000 so I was like okay then. I could only find pdfs from university libraries I don’t have access too. So I’m glad my school has a physical copy.
Idk if I can describe how useful this book is. It’s all illustration. The only text is the labels. I have a really nice book on insect anatomy but it’s like your classic textbook
Like very useful but it is still a pain to flip through a thousand page book looking for images but it’s mostly text. There aren’t nearly as many diagrams. It doesn’t show you nearly as many angles. It doesn’t show or label even close to level of detail the one above does.
In case anyone hasn’t read my tags: I’m going to scan this whole book and make it into a pdf. You all can have it for free. It will take a while. Bear with me.
