Leptictidium: A Strange Dawn for the Age of Mammals

Leptictidium is one of the most famous of the strange mammals diversifying after disaster. But how did it live, what was it, and why did it go extinct?
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[@blazingtrs6348]

imagine if these guys became succesful to this day and radiated to different niches. we would have mammalian theropods

[@SoulDelSol]

We do. Kangaroos

[@mhdfrb9971]

Well we get a giant Kangaroo back then

[@blazingtrs6348]

​@@SoulDelSol a kangaroo's posture is more like a retro 1920s t rex. pangolins are more accurate to a theropods stance i feel

[@jesselaw2575]

​@@blazingtrs6348 but we're also putting spinosaurus back and forth between these. So maybe not therapods over all?

[@bmolitor615]

boing boing boing

[@howardrsims]

a million years from now if someone were to find the fossils of a chihuahua and a saint bernard, would they think them different species?

[@TiagoH1710]

Probably 2 spp. in same genus

[@RaptorChatter]

Probably. But that's a really interesting case since they were bred specifically for those traits, instead of natural selection changing them over time. So it's hard to use those sort of modern breeds of domesticated animals, and apply the same framework as used with fossils.

[@etinarcadiaego7424]

"This one is CLEARLY the larval form of the other one."

[@princesseville6889]

​@@etinarcadiaego7424 and then they find a baby chihuahua and be confused as all hell xD

[@Vulcano7965]

You'd probably conclude that these are artificial breeds since the huge varieties would just suddenly appear for a very short time period and dissapear just as fast. Especially because you would find these different breeds in the same area, competing for the same ressources. Meaning it would be very unlikely they evolved these forms for niche partitioning (we can conclude their diet by looking at stable isotopes in e.g. their teeth). Now there would be probably a debate how truly distinct these breeds were and if they could interbreed or not.

[@toonrex2806]

Lepticidium also appeared in the Jimmy Neutron episode "Sorry Wrong Era".

[@sigilhunter3199]

"I'm gonna call him Leppy"

[@WRPBullet]

When I was tossed into the Cretaceous era, I was filled with fright and “terra”

[@sigilhunter3199]

@@WRPBullet "But then I met a friend who helped me to survive"

[@SliceySlicer]

Lol

[@MaddysinLeigh]

I was disappointed by the lack Jimmy Neutron references

[@Itsjustme-Justme]

Cute ancient, cat sized elephant-kangaroo 😍 Isn't it crazy that I have never been living more than half an hour away from Messel, have seen a lot of fossils in the Darmstadt and Karlsruhe museums, but still haven't visited the Messel pit and museum yet?

[@RaptorChatter]

I get that. It's one of those things where you can always visit it so you don't because you can always do it later

[@sociallysatanic]

sounds like you need to plan a daytrip my friend ; )

[@jefffranklin4894]

It is literally a Tatooine Womp Rat from Star Wars

[@SephirothSuperKool]

Thats what I thought!!

[@jjk28141984]

I used to bullseye these things in my T-16 back home.

[@differous01]

The hole in the skull beneath the eye socket is seen in many snouty species (Elephant Shrews, Elephants, Tapirs, Anteaters, Armadillos, Glyptodons..) but what Leptictidium most resembles (bipedal, long tail, coming in a range of sizes) is a Pangolin.

[@mhdfrb9971]

I hope next time you can discuss about Eudibamus Cursors, the earliest known bipedal vertebrate in the early permian. That's way back before Archosaurs evolve bipedalism in the Triassic.

[@f.u.m.o.5669]

It's a lizard knockoff. It does not deserve love.

[@cassidyjones2730]

@@f.u.m.o.5669 weirdass take dude

[@f.u.m.o.5669]

@@cassidyjones2730 Didn't mention the fact that it lived before true lizards.

[@Fede_99]

@@f.u.m.o.5669 L take

[@Fede_99]

The earliest known bipedal vertebrate is Cabarzia which lived even earlier at around 295 mya. Also, many Archosaurs became obligate biped while animals like Eudibamus and Cabarzia used bipedal locomotion only occasionally

[@robrice7246]

2:19 I believe that New Dawn from Walking with Beasts was filmed in Java. Although would Florida's Everglades serve as another example of what North America & Eurasia climate and environment may have looked like during the Thermal Maximum?

[@danielmalinen6337]

Walking With Beasts taught many wrongly and inaccurately that Gastornis was a terror bird and preyed on Leptictidium, when in reality Gastornis was a giant herbivorous duck that had evolved to be bigger so that it could pick nuts, corns and seeds from trees and its beak became big and strong so that it could crush them. It is more likely that Gastornis lived in peace with Leptictidium, and Leptictidium ate the remains of leftover fruits that Gastornis dropped from trees in search of chewable seeds.

[@bustavonnutz]

There's no concrete evidence that Gastornis was a herbivore, it's all guesswork.

[@basithardimasqi6751]

I'd be more surprised if the series are still considered up to date now.

[@benzelwasington4059]

Even so Im sure it wouldent had minded some meat in the diet lot of herbivore birds eat meat if given the chance

[@Devin_Stromgren]

@@benzelwasington4059 Ever deer and cattle will eat meat given the chance.

[@aceundead4750]

I thought the most famous depiction of leptictidium was in Jimmy Neutron.

[@RaptorChatter]

We realized it was there after we had recorded everything. I with I had remembered that earlier though to include it.

[@sharendonnelly7770]

Imho, I am leaning toward hopping as opposed to running in leptictidium. Modern animals like kangaroos, have shorter femurs and elongated tibia/fibulas. Theropods had nearly equal length of femur to tibia ratio. Leptictidium has visibly shortened femur and longer tibia. The lack of fusion of the tibia/fibula may be an indicator of the evolution of this mammal, and show how strengthening of the lower leg by fusing the two bones improved hopping in subsequent generations.

[@bustavonnutz]

Additionally, the hip joint argument isn't very compelling, as that paper made the assumption that hopping animals *had* to look like either Macropods or Frogs to hop around; completely erroneous assumption, but hey this is modern Paleontology we're dealing with.

[@miquelescribanoivars5049]

To be fair, a lot of birds have shortened femurs and are walkers.

[@leobuana7430]

​​@@miquelescribanoivars5049 won't the difference in structure between bird claw and mammal feet change or factor into that ?

[@frip1080]

Im so glad this isn’t a April fools vid this little guy is so cool

[@IMADINOSAURNOTABIRD]

Bruh the turtles got caught in 4k💀

[@tobiasware]

Very interesting subject, and well thought out, Ezekiel. I look forward to watching and learning about paleontology, and your style makes learning such a pleasure, thank you.

[@TroyColey]

Leptictidium is the GOAT

[@eliletts8149]

Wait, I thought that placental mammals had already evolved before the K-Pg extinction event?

[@RaptorChatter]

Probably. Genetically, they go back to before the extinction, but we don't really have fossils that are confidently placental mammals until after the extinction

[@eliletts8149]

@@RaptorChatter oh, interesting! Thanks for the information!

[@YochevedDesigns]

I love you for saying "non-avian dinosaurs." On behalf of the cassowary and their kin, thank you! 🐔

[@Qualimar]

Leptictidium: the mammal that wanted to be a dinosaur.

[@ekosubandie2094]

Wouldn't that be pangolin and armadillo though? The former at least can walk on two legs

[@paulwallis7586]

As an Aussie, a non-hopping animal like that is a bit of a revelation and a bit of a hoot. Glad you explained the issues, because otherwise you're left with the problem of why an animal like that would be bipedal. What use would that be? How would the bipedal posture work?

[@rileyernst9086]

Short faced kangaroos did not hop. So it is not unheard of.

[@garlicjr9686]

Very interesting video. I think that a mention to the presence or absence of epipubic bones (or even a baculum) should have been made during the phylogeny part. I think that would be a good indicator of just how related were these animals to the known placentals. Even if that wasn't enough to pinpoint their location on the phylogenetic tree, that would be interesting to know.

[@tamirisgaelzer1902]

I love learning more about lesser talked about mammals!! Great video!

[@rhoff523]

Outstanding presentation showing how science works as well as interesting facts!

[@kendrickwood7174]

“When I first came to the Cretaceous era I experienced fright and terra’ and then I met a friend who helped me to survive His blood is warm His young are born alive Hey o! Aha Hey hey hey hey o!” -Carl Wheezer

[@sauraplay2095]

Nice video raptor!

[@sciencenerd7639]

Saltatorial. What an awesome word. Great video, thank you so much!

[@RaptorChatter]

It can be even more fun! When big sand dunes are made we say that the organization of the sand grains is made by saltation! It just means little jumps.

[@matthewbromm7552]

awesome vid man thankyou

[@stormevans6897]

Man, I remember watching that special when it premiered as a little kid..

[@frogbean5532]

I would never understand these words outside of this topic

[@suggiethames9870]

OMG I love that little critter, it reminds me of Gonzo from the Muppets

[@violetnightmare9216]

It would be really cool to see a taxonomy video discussing how taxonomy works and the difference between types of taxonomy and the "are birds reptiles?" question.

[@maozedong8370]

I will answer that question quickly. Nature doesn't give two sh*ts about how some hairless apes like to group things. If birds are reptiles, that means that humans are too considering some of our earliest ancestors on land were reptiles. We'd also be amphibians and fish etc. See how it works, it is just nonsense. That is why we tend to go with the whole form is function thing. Birds are NOT reptiles because they have deviated greatly from the typical reptile much how mammals have deviated from their amphibious and reptilian ancestors. We only discuss taxonomies where they are relevant and depending on what we are doing. If you want to study birds, you don't go and study the lizard scurrying around in the woods do you? Even if birds and it have a common ancestor like any life form does with one another, species branch out because that is how evolution works. Not all reptiles evolved bird-like adaptations did they? That is because only a single group of reptiles evolved the adaptations to become the ancestor of modern birds today. Therefore, how could you class a group of highly specialized reptiles that have long since deviated from what a reptile even is, a reptile? You wouldn't which is why people don't ever refer to them as such unless they are talking about their genealogy.

[@LuisAldamiz]

The answer is avians are indeed reptilia. Otherwise whatever...

[@violetnightmare9216]

@@maozedong8370 If you want someone to read a comment/reply that is that long, don't start out by being kind of rude and abrasive. I also did my own research and wasn't looking for an answer from the comments, I was suggesting that Raptor Chatter do a video on it because it is a natural question that a lot of viewers probably have from him mentioning non-avian dinosaurs all of the time, not soliciting answers from random commenters.

[@bassmantjox1299]

@@maozedong8370 they are reptiles because taxonomy change since the 19th century they are reptiles because firstly, they’re dinosaurs, secondly they’re closer to squamates than to mammals and finally they’re diapsids which has every single living reptile. In your logic dimetrodon is reptile do to how similar it is to lizards

[@maozedong8370]

@@bassmantjox1299 It is as if you never read a SINGLE word in my comment. They are NOT reptiles.

[@johncaze757]

Hey wasn't that animal in an episode of Jimmy Neutron?

[@dustinfisher29]

Those little buggers look like Bilbies in Australia. .

[@cowpoke3611]

WOMP👏RAT👏

[@NeoMorphUK]

This thing looks like a Pangolin without the scales.

[@marilynlucero9363]

Leptictidium are adorable.

[@landoftheninja]

*Actually* this species most famous showing was Leppy in Jimmy Neutron

[@shinaniganz4453]

Can you make a video about dinosaur overheat problem? Like how they likely deal with it since they're so big aspecially sauropods. Thankyou

[@maozilla9149]

nice video

[@spartan1986og]

Perhaps the ground cover was affecting the need to fuse the two bones. Here in Oregon we have fossilized lahars from that period and they show very deep leaf litter on the ground. This might have functioned like a gym mat and absorbed a portion of the jump force. But how would one even start to prove that? Wowzer.

[@RaptorChatter]

You'd need to look at the paleosols in the area surrounding the Messel Pit, but as far as I know there isn't anyone really doing that, and depending on the rocks it'd be super hard to prove still. You'd basically be looking for trace elements and using that as a proxy for how much leaf litter there might have been.

[@petehoover6616]

When you see how we know early man was bipedal because of the angle where the femur meets the knee is tilted while it is straight in a chimpanzee that matches every chicken or turkey drumstick you have ever seen. I have pet finches. Their legs are wide set on their bodies and their femurs are straight like chimpanzees' are. They must hop because if they pick up one foot they will fall over. American Robins and starlings have tilted femurs. Every bird that steps does. Sparrows have straight femurs. Every bird that hops does. Leptictidium had tilted femurs, I think.

[@f.w.ordemorton8057]

Isn't it possible to have articles written in French or German translated electronically? It can certainly be done with whole paragraphs.

[@teawrecks1243]

the walkabies from "Hamster's Paradise"

[@mns188]

I really need to go back to the senckenberg museum, it's been 20 years. They have a huge collection of messel fossils. As a kid I didnt pay much attention to them, but as an adult I'm really interested. I seriously don't know why I didn't already got to do that, it's only an hour away.

[@RaptorChatter]

Sounds like a great trip for a day off! I'd love to check it out, but I'd need to plan around international flights more.

[@matthewjohns1758]

Each of the species of Leptictidium might have branched off to begin a different species. Since they were so successful and it was a time of mammalian creation they might have just changed into another animal all together.

[@s.b.7987]

6:57 Cries in Pangolin

[@X3MgamePlays]

"Just look at that snout!"

[@user-account-not-found]

I want this as my familiar.

[@murderyoutubeworkersandceos]

All the sinue and ligaments holding our ankles together and we humans still walk, not hop

[@abdulazizrex]

When I first saw Walking with Beasts, I thought leptictidium was related to kangaroos!

[@scvcebc]

Perhaps it was a marsupial, it sounds like we don't really know yet.

[@Edmontosaurus_enthusiast]

Why does that literally look like a dinosaur it’s amazing

[@cgyoboi]

This video made me realize something... If Lions weren't alive today we probably wouldn't know that they lived in prides, we would probably assume they were solitary like all other big cats.

[@RaptorChatter]

Probably. We think that some of the sabertoothed cats my have lived in groups, but at least part of that is based on them taking down large prey like young mammoths, so still nothing concrete.

[@BatKraken742]

It looks like a scurrier from Star Wars.

[@henryJBonaparte]

I call them... KANGASHREWS!!

[@YouTubePurgetheblackplague]

It's a star wars creature. Also, limestone mines are full of fossils

[@origaminosferatu3357]

Body Horror level 1: This little rat-roo walking around like a therapod. Body Horror level 2: A massive f off therapod bunny hopping like a rat-roo.

[@Mecharnie_Dobbs]

It sounds more like a metallic element than an animal.

[@uwustomp5528]

Carl wheezer voice* I'm going to call you leppy!

[@benw9949]

Are we sure that little critter was that bipedal with legs that upright and stretched out? Couldn't they be hoping, jumping animals like. jerboa or a rabbit or a jumping mouse? But either way, that's sure interesting! And I'd wonder if they evolved further, as jumping or bipedal animals, and what they became, or if they died out entirely. It'd be interesting to have those little guys around today. Funny little nose like a shrew or elephant or aardvark, biped or hopper, other neat adaptations. Sort of rodent-like, maybe? 1, 2, or 3 feet long. Weird, cool little critter. Neat idea for a movie critter or TV series critter, mascot, pet, livestock,.

[@rickwrites2612]

8:50 he explains the hopping possibility and why it's not as strong hypothesis re skeletal features.

[@ramonsanchez6903]

Great video don't worry I'm trying to learn some languishes like Japanese

[@Poltard]

The “critter”

[@GenghisDon1970]

good video! It would be great if you weren't handicapped by lack of access...we need good scientific translations of those French & German papers. No good excuses they haven't been done.

[@scvcebc]

Technical translation is still a specialty career, but future AI may help automate that in the future. By then, all jobs might be obsolete, though!

[@justinwatson1510]

It's the tyrannosaurus derp

[@WileyCylas]

He looks like Gonzo the little Muppet & I want him

[@RaptorChatter]

Muppets fossil documentary when?

[@MaddysinLeigh]

It’s Leppy! Now I want a put on a grass skirt and dance with it

[@gillablecam]

What is leptictidium? It's the rhythm for the ostinato at the start of Duel of the Fates

[@RaptorChatter]

Lol

[@user-account-not-found]

Do you think it could survive the day after baked beans night?

[@MikeWazowskixxx]

Jimmy neutron animal I love it

[@joshuavarney2346]

Clearly mammals tried to make a 1 to 1 copy of the dinosaur build lol

[@wlb2j]

If they didn't survive, then how do we explain elephant shrews?

[@RaptorChatter]

Not directly related, but potentially relatives. From what we see with the fusion of the limbs, the teeth, and the extremely long tail it's not likely that they led directly to elephant shrews, but could have been closely related to the elephant shrew ancestor.

[@noaholson9047]

I really wish I had a time machine and a DNA kit so I could map out the genealogical tree of life and where all these creatures fit taxonomically speaking

[@scvcebc]

My fantasy is that aliens have visited the earth periodically to do careful, non-interfering research to document and take tissue samples from life that died naturally or was common enough not to be affected by taking an occasional sample. Then someday, they would return to find that intelligent life had finally evolved and they could share all that history with us! However, the progress of our own science has been so amazing in the past 100 years that we are learning more about the past than we ever used to think possible. Who knows what future techniques will be developed to learn even more? Learning more answers always leads to asking new questions though, it never seems to end!

[@petersmythe6462]

Tell me the fossil doesn't have a vaguely dinosaurian vibe even though it's a mammal.

[@immagical7036]

What the heck it’s like a anteater-faced kangaroo Also, I have a funny hearing condition that results in certain sounds blending together. It’s especially bad with accents from places I am not Apologies but what are you calling the pit?? “Mess-ell” or like, “mussell”/“muscle” etc?? This is not your fault, I just have trouble distinguishing between similar sounds

[@RaptorChatter]

Messel Pit It's the name given to the fossils where many great ones in Germany have come from.

[@immagical7036]

@@RaptorChatter thank you lol

[@lorinctoth9402]

Sneef norf!

[@neomt2]

The bbc documentary accused gastornis of being a predator of small horses and leptictidium without evidence 😮

[@RaptorChatter]

Considering a lot of the other early large birds at that time it's not shocking, but yeah, it is a bit unfair.

[@f77ddngeod888]

Tyranoshrewrus rex

[@beachboy0505]

Time capsule, missing link

[@sullyboyzzz]

The kangeroo from Rayman?!

[@TroyColey]

❤❤❤❤❤❤❤❤❤❤❤❤

[@martinbelmonte6774]

Velocirattus

[@davidbamford4721]

What and where is the mussel/muscle pit that you speak of?😊

[@Xerxes2005]

Messel Pit, in Germany.

[@B1T3F0RC3]

Made a super dumb phrase as a kid bc I kept hearing it wrong lolol, was the "electric tiddy mouse" it was funnier when I wasn't allowed to say it near adults tho pfft

[@MrChristianDT]

Well, from that picture in the thumbnail, it kind of looks like a kangashrew.

[@BBLeviathan-Gaming]

Huh, anyone got Luke Skywalkers number? We have a womp rat infestation

[@jbrecken]

They should have named it kangashrew

[@ramale-cv4nh]

This bro from Jimmy neutron

[@SockieTheSockPuppet]

Raptor-shrew.

[@michaelharper8503]

Marsupials, like eutherians, do have placenta.

[@SwampApeSci]

We all know it wasn't WWB but Jimmy Neutron that popularized Lepti

[@eldritchangel4058]

It's second most famous appearance was in the Jimmy Neutron tv episode, Sorry, Wrong Era.

[@australianoz]

Chuck in the link to the French material. I'll translate it for you

[@leannasullender9230]

This appears on the adventures of Jimmy neutron boy genius.

[@dannybright8708]

I first learned about this animal from Jimmy Neutron!

[@nilsgensert5814]

If you can get me the german papers, I can translate them for you, I am a native german, technical writer, translator and science communicator.

[@jeffgoode9865]

Zach Hadel!

[@ericvondell5157]

"What the Hell is Leptictidium?" This title and the freaky "Kangaroo Rat" looking thingie made me, Instantly, say: "LUNCH!" (I found this while searching for a good color pattern for a Dinosaur Doodle.....) Then I thought that the name Would be great for a rare Vital metal from a planet in a sci-fi movie! 🤪💞🛸

[@carolynchurch4642]

Person: it was small, fast, and it had red. Humans: it must be a leprechaun! The secret society of surviving leptictideum: they called us a what?

[@XanderDorn]

If you need something translated from German maybe I could help you out.

[@sammorrissey9094]

Jagwire. Lol

[@RaptorChatter]

Other accents exist 😱

[@agathoklesmartinios8414]

Leptictidium looks like when you copy someone else's homework and just change it a bit.

[@MrFleem]

Maybe they were nasobames. [That was a joke]