Meet Flipper. He’s a happy-go-lucky guy who’s only ambition in life is to cruise the water for a bite of squid. He loves to greet new friends with a friendly splash.
It’s a dolphin! It’s a shark! It’s a…dinosaur?
Flipper isn’t any of those things! So what exactly is he anyway? Flipper is part of a unique-snowflake group of animals called Ichthyosaurs (think Ick!-theosaurs). Basically, a group of reptiles that were so well-adapted for a watery lifestyle that they look similar to other, equally well-adapted sea critters- like sharks, fish, and dolphins. It’s the body style that works best if you live your entire life in water, so they tend to look similar. Let’s take a look at some of those similarities, and what makes them so different!
So what’s the same?
I think everyone can agree that all three have the smooth, torpedo body style. They have powerful tails to push them forwards, and they all have at least one dorsal fin (the one at the top), and two pectoral fins (the “arm” fins). In short, they all have a body plan that is ideal for a life in water.
They all have sharp teeth and excellent senses for tracking down and chasing other aquatic critters for dinner. It varies depending on what’s more plentiful at the time, but there are definitely no peaceful vegetarians here.
And they all give birth to live young- even some sharks- though it depends on species when it comes to sharks. Ever heard of mermaids’ purses? Those are shark eggs. 😀
Ok, so sharks need a quick explanation. Most have eggs, but only a few actually lay those eggs. What does that mean? It means most sharks have eggs, and most of those mamas simply hold onto those eggs until they hatch, and then keep the babies inside just a bit longer until they’re big enough to be born and take on the ocean.
A few sharks don’t have eggs at all, and the embryos develop inside just like mammal infants do. Some of them even have a placenta, which is a very special organ mostly unique to mammals. It’s a bit like a giant yolk sac and liver in one- it feeds the growing baby, filters out toxins, provides oxygen, and a whole host of other subtle things that makes an extended pregnancy run smoothly. 🙂
Which makes me wonder…how did Ichthyosaurs do it? It’s food for some healthy speculation, especially since there is so much variation in how some reptiles have live births too.
- Skeleton- take a look inside and you’ll see bone for dolphins and Ichthyosaurs, but sharks have mostly cartilage. The same stuff that gives shape to our ears and noses.
- Sharks have gills, but dolphins and Ichthyosaurs are air breathers.
- Tails- a dolphin’s tail is horizontal compared to it’s body, but sharks and Ichthyosaurs have the verticle tail flukes. Plus Ichthyosaurs have bones in only the top fluke of their tails.
- Fins- Dolphin has the least number of fins, one dorsal and two pectoral. Ichthyosaur comes next with one dorsal, two pectoral, and two pelvic fins. A shark has two dorsal fins, two pectoral fins, two pelvic fins, plus the little anal fin.
- Skin- Dolphins have smooth skin, a bit like wearing a wet suit. Sharks have scales that look smooth but feel a bit like sandpaper. No one really knows what sort of scales or skin Ichthyosaurs might’ve had, but it would’ve appeared smooth like dolphin or shark skin.
- Blubber! There is some evidence that Ichthyosaurs had blubber like dolphins do. Here’s a link to the paper. 😀
- Fish vs. Reptile vs. Mammal- Sharks are fish, Dolphins are mammals, Ichthyosaurs were reptiles.
So it’s not a shark, fish, or dolphin, but is it a dinosaur?
Ichthyosaurs are not dinosaurs! Take a look over at my “Which One is the Dinosaur?” post for a more in depth explanation as to why, but the short answer?
Crocodiles and birds are closer on the family tree to dinosaurs than Ichthyosaurs were. Birds are basically highly specialized dinosaurs that survived the mass extinction, and crocs are part of a line of critters that were the great gran-daddies to dinosaurs. So not dinos, but close relatives.
Ichthyosaurs are something else entirely. They were reptiles specialized for life in water.
The clock is ticking! Only two more eggs to go before Babysaurus is here! 😀 I’ve been hard at work trying to get my buffer done so that we can still enjoy a COTM once Baby gets here. 🙂 Since I’m working on other monthly posts as well as the current month’s posts, I may be a lot quieter than usual when it comes to answering comments. I do try my best to answer them when I can though, and I read them all! Thank you for visiting! 🙂
You know Spring is here when chicks are around! I thought I’d share a bit about the domestic dinosaurs I keep around here. 😀 And another reason I’ve been so busy lately.
My new chicks arrived in the mail just a little over a week ago. 25 Cornish X roosters. They all have the same name- Chicken Nugget, or Chicken Pot Pie, or Chicken Enchiladas…Basically “insert favorite chicken meal here”, because these little guys are destined for a comfortable, but short life.
We don’t usually buy meat for a number of reasons I won’t bore you with here, so that means we normally have a lot of axis deer meat from a lovely hunter friend of ours. This pregnancy I’ve had a pretty fierce craving for chicken, but I don’t like the living conditions the poor birds at the grocery store have to suffer through before butchering day, so I thought we’d try our hand at raising our own. 🙂
They’ll have sunshine, a sheltered space to run, grass and dirt under their feet, bugs to chase…basically as good a life a chicken can have, just like our lovely egg layers. These chicks will have just one bad day, and we’ll have a freezer full of healthy, happy chicken.
Knowing where our food comes from is a valuable lesson here on the homestead, and I like trying to grow a garden too. I just have much better luck when it comes to critters…most of my poor plants don’t make it to harvest time. D:
Here are two of my girls. I love how they have that stern gaze, so prehistoric! They are great egg layers, and I love watching them peck at bugs and grass in the yard. The only downside to letting them wander where they please is that they also poop where they please.
Down below is Big Daddy, and he always keeps a close eye on his girls. You think a velociraptor’s claw looks vicious? Well this big guy has a set of spurs that are every bit as nasty if he really has a mind for it. Good thing he has a healthy understanding that I outrank him. 😀
Coming Next Week…
This little dino likes to party!