#caudal posts

[lecaudal]

[maple-leaf-in-autumn]

bitches out here being polytocous

[kragehund-est]

moray eel appreciation post! there are approximately 200 species of moray eels and they're all stunning in different ways

even the ones without fancy patterns have these adorable little faces. so lovable

moray eel facts:

they have two sets of jaws, which inspired the xenomorphs' second mouth in the alien franchise

the largest species of moray eel, the giant moray, can grow around 10 feet long

the dwarf moray eel is the smallest and is around a foot long

the reason morays always have their mouths opening and closing is because they have no gill covers, this action forces water over their gills so they can breath

moray eels have no pectoral or pelvic fins, and their dorsal, caudal, and anal fins are fused like one long strip along the entire body

[manusuchus]

A speculative arboreal crocodylian

A year ago I began my research on the Mekosuchians, especially around the genus Mekosuchus and my already very strong skepticism at that time about the claims that they were tree-dwelling crocodiles (Something extremely improbable and which I may comment on another occasion. For now you can read in depth about Mekosuchus in this post by Armin).

At that point I wondered ; what would an arboreal crocodile really look like if it existed? 

I decided that it would be a derived member of the subfamily Caimaninae, specifically belonging to the Jacarea clade (which includes all species of the genus Caiman and Melanosuchus). 

The body has evolved in a convergentely with squamates such as Varanus salvator, being thinner and more elongated than that of any other crocodylian, following the same process the tail : Once the motor that propelled it underwater, is now becoming something similar to a whip that allows it to maintain balance on the branches, losing the characteristic single and double caudal crest whorls, to the point of almost disappearing.

The dorsal osteoderms are shrinking, but are still visible and play an important role in the ecology of the animal, helping it to thermoregulate. 

The limbs have been considerably widened and strengthened, an adaptation very visible in the metatarsals of the hind legs, which, together with the sharp, curved claws they have developed, help the animal to cling effectively to trees. 

The skull is the most distinctive part of all, as it has not only become shorter and more robust as a whole (Males have even developed an anteorbital crest similar to that of some members of the genus Crocodylus such as C. acutus or the extinct C. checchiai ; very likely some kind of sexual dimorphism), but it is developing unique characteristics such as binocular vision, zyphodont dentition and laterodorsally positioned nostrils, all of these attributes usually associated with terrestrial hunters (although there is not a necessary relationship in all cases), thus moving away from the semi-aquatic lifestyle.

Despite this, these crocodiles are still dependent on water to a certain extent, always inhabiting the forests near the rivers and being able to swim perfectly well if necessary, just like the extant iguanas and monitor lizards.

If I had to add some kind of worldbuilding that allows the existence of this animal, it would probably be located millions of years in the future : After a cataclysmic event related to climate change, South America has suffered a process of desertification in which large bodies of water have dried up, forcing the very abundant babas (Caiman crocodilus) to move into the remaining forests and jungles, adapting to a more terrestrial lifestyle. As an isolated population of these caimans chose the birds and monkeys as their preferred prey, they would gradually follow them to the treetops.

After a few more million years, the land has recovered, and large rivers and lakes are once again flooding South America, favoring the emergence of large tropical jungles again, opening a new world for these tree-dwelling caimans. Will they manage to adapt to the new climatic conditions or will they become extinct as a consequence of this and other factors such as the emergence of new species of placental predators that threaten to occupy their niche?  Well, that is uncertain.

The illustration was made in gouache and watercolors during September 2022 . I scupted a small-basic figure made in clay to in order to facilitate the understanding of the lights and shadows.

Here are some pictures of the process:

[dragonthunders01]

Spectember D5: Sexual Selection

Through the different timelines, there is an alternative world that witnessed a deep ice age in the Permian caused by a prominent shift of the continent crust moving Pangea down into the south pole and blocking ocean currents, worsening the life conditions and turning most of the continent in a tundra, in the aftermath when the position of Pangea returned to something like its original position life was changed greatly, as unlike in our timeline earth was not suffocated in fire but got cold so a new variety of animals developed and survived.

In the oceans, Holocephali had a resurgence post Permian mega ice age, as their groups did not suffer horrible, things like Petalodontiforms, Eugeneodontids and other did not perish, but then there were other more varied forms evolving too, some sample are within Chimaeriforms which they in a better spot now that they aren’t relegated to the deep ocean but as diverse surface dwellers, some groups started to exploit their clasper structure in ways that would make them look almost unfitting for survival, this as a response of sexual selection. From there, a new group evolved, the Clasperantlers (Delirocephalia)

They are short body forms, small caudal fins but with large pectoral fins, these have the peculiarity that male claspers now have become these super elaborated ornamental structures that works mostly for exhibition or fight, depending of the species. They derive from ornamental structures around the orbits and the whole dorsal fin spine that developed into an articulated claw-like structure, something resembling the ornamental spines of Symmoriiformes but capable of movement.

The most common species is the Pentanichecephale monstruorum, small in size, about 30 cm in length, females look pretty much average to a chimaera with short tail, with a small dorsal fin, but the male in the other hand possess an ostentatious arrangement of 5 long horn-like structures, being 2 pairs growing around the orbit, with the middle 5th one the derived dorsal fin. They tend to be moderate in size but when mating season approaches, they start to grow in size, being covered in layers of dead tissue and useful against other males, they can break and regenerate, males often have to stand multiple fights before mating with a female which can hold with the 5th horn.

[anomalocaris-here]

ok so like many people on here i'm very autistic abt fish (and other animals) so i'm gonna just start posting my notes app infodumps on the fish autism website

Definitely one of the goofiest sharks out there, i've gone on record as claiming the pelagic thresher (Alopias pelagicus) as my favorite shark. Threshers are known for their extremely long tail, which is used to help catch prey. The thresher uses its tail like a whip to stun groups of small fish. Points for creativity!

The pelagic thresher can be identified by dark patches of skin around the base of its fins and smaller eyes than its relatives. Perosnally, I would describe the species as looking like its mom just left it in line at the cash register to go grab something she forgot. Delightful lil guys!

Sources/further reading:

https://www.nationalgeographic.com/animals/fish/facts/pelagic-thresher

[ildarotyrannus]

I apologize for such a long delay. I couldn't find the motivation to keep posting here. But, as I promised in my last post, here are three more drawings made for last year's scientific conference. :)

Front half of Dakosaurus andiniensis, massive metriorhynchid from Late Jurassic of Argentina. As with Cricosaurus, I based this reconstruction on metriorhynchid specimens with skin. Note the presence of speculative skin parasites, whose marks were founds in fossil skin. Also, there are salt glands in antorbital fenestra. This feature is based on this study: https://anatomypubs.onlinelibrary.wiley.com/doi/10.1002/ar.24678 BTW, some recons portray Dakosaurus with crocodile-like facial integument and some recons even have "lips"! I decided to diversify from these both options and did it with smooth streamlined skin.

Prognathodon sp. reconstruction based on purportedly juvenile specimen with soft tissue outlines from Late Cretaceous of Jordan. This small individual was described in this paper: https://www.nature.com/articles/ncomms3423 Preserved skin impressions include silhouettes of the skin fringes of the flippers and the caudal fin. The caudal fin is quite small, but in adults it could be proportionally larger. This finding confirmed that mosasaurs converged with ichthyosaurs and metriorhynchids to develop a fish-like caudal fin.

And finally, Seeleyosaurus guilelmiimperatoris (formerly species of Plesiosaurus), a microcleidid plesiosaur from Early Jurassic of Germany. Holotype of this species is almost complete specimens with some skin impressions including rhomboidal skin flap. Perhaps all plesiosaurs had caudal fins of one form or another. However, their orientation is controversial: many paleontologists are of the opinion that the fin was vertical, but others think it was horizontal.The arguments in favor of the second point of view are the rigidity of the chest, the flat and wide shape of the tail in the proximal part and the absence of bending in the distal part of the tail: https://www.researchgate.net/publication/339423536_Peculiarities_of_the_Structure_and_Locomotor_Function_of_the_Tail_in_Sauropterygia I decided to choose this version for reconstruction. Which of the scientists is closer to the truth, new findings will show. All of these drawings were done with black gel ink pen and black colored pencil with small additions of white gouache.

[mh-dreamscape]

Fun fact brought to you by a marine biologist/marine affairs major!

Part 3: Creature from the Black Lagoon Edition!

Sooooo I ended up getting her and when I finally got to look at her details up close, I got inspired to do another one of these! Now that I’m graduated, I’ll most likely be taking her out of the box at some point! This will also be a little bit of a review too!

In my previous post, I rated her a 9.7/10 because I was confused by some design choices, like the harpoons in her heels. I feel that would’ve looked better with some type of shoe unless her feet are supposed to be like boots? Anyways, I’ll be going from head to feet with aquatic biology and my feedback!

The Fin Headpiece:

Most fins have multiple lines or filaments like that and tend to start with either a darker color or color that matches their body on the inside. That color starts to fade out the further on the fin we go because the material is a lot thinner. They can appear to have a sheen look sometimes because they can be shiny and reflect light a little!

The Face:

Probably the most informative part, the face has many qualities to it! Makeup? Iconic. Flawless. The only thing I might change about it is maybe a not-as-bright lip color, but I think I feel that way about many designs and might just be a personal preference so I’ll let it slide. Aquatic factors? To. The. MAX!

Unless a fish has a protruding lower jaw, they don’t typically have an upturned smile. Body shape and mouth position can be linked together too. Bottom feeders, like catfish and sturgeon, are usually wider and flatter with an inferior mouth or a mouth that’s toward the bottom of their face or completely under it. Fish with superior mouth types (“a” in the picture and towards the top of the body) and terminal (“b” and towards the middle). As you can see, either way, the fish will have a downturned mouth and I just love that quality on this doll. This follows with her nose as well! Her nose does stick out like a normal monster high doll. It’s flattened a bit and has wider nostril sides which goes along with the snout on fish.

Now, I know most of her design is literally based on the Creature of the Black Lagoon so I’m probably just listing facts about him too, but let’s talk about the sides of her face, the part I highlighted the most in this 3/4 perspective!

Probably the most prominent features on her head sculpt: Gills! They generally follow the rules of anatomy having the the arches and filaments, but she is missing an operculum, which is a protective covering for the gills made by a series of bones. This doesn’t mean she’s entirely inaccurate though as only bony fish have operculums!

The Hands:

While it isn’t related to fish much, I wanted to admire her hands too! On Mattel’s page for her, they mentioned amphibious a couple of times so I thought I should show that. This is a comparison to frogs hind leg and foot (I couldn’t find a good picture of a “hand” or front leg).

The Body/Clothes:

As mentioned above, this piece was called “Pearlescent amphibious body armor” and while it does resemble a frog-like skeleton a bit, I felt it looked more like a fish! The top part that rests on her shoulder reminds me of the head portion of the skeleton.

Now, let’s take a look at her tail/fin which I believe is made of some type of tulle, but please correct me if I’m wrong! I don’t know much about fabrics.

The way the tulle sticks out in the first set of body pictures (middle one) reminds me of a caudal peduncle which as described in the picture above, connects the main body and the caudal (tail). The way the tulle is spread, it looks like it would be a truncate tail. Tail shapes are connected to the maneuverability and speed of a fish and each in the third picture shows how they could work. I know it probably doesn’t lay that way when she’s taken out of the box, but it was a cool design choice!

The Feet/Shoes:

I haven’t taken her out of the box yet, meaning I don’t have any good pictures of her feet or the stand so I’m using the stock photos from Mattel’s site. The fins follow fish biology with them being a lighter or different color and the tops and bottom of her feet/shoes resemble a more amphibious or reptilian nature. Taking a closer look at it, I can now see that the harpoon is attached to a rope that wraps around her ankles! I wish they colored it differently so we could distinguish that (or maybe I was the only one who thought they just stuck harpoons in her heels lol). After finding that out, I don’t have much complaints. I think it’s kind of cool they made the feet into boots!

The Stand:

I adore the stand! I love when stands can add a bit of background or a pop of color to the doll! The kelp/seaweed was a great idea to hold her up and there’s detail on the sea floor as well! My only tiff is that I don’t quite know how stable this will be. With the usual stands, the clamp in the back holds their waist up while the bottom gives their feet something to rest on. It makes it stable in general posing of dolls. These pictures show her feet barely resting on it and I’m sure you could probably stretch her one foot out to land on the higher part of the terrain, but it wouldn’t quite look as good as the stock.

I tried making a quick edit of another way to keep the pose. I originally wanted it to be a harpoon and harpoon gun but I felt that was sort of off brand with Mattel and Monster High so I instead lifted that anchor from the terrain, colored it differently to look like it was covered in algae, and rested it in the seagrass! The only drawback would be that it requires a bit more plastic for each stand and may make it a little more clunky. Like I said, I haven’t taken her out of the box yet so I don’t quite know how stable the original stand is, so this is more so brainstorming!

Overall:

Making this post made me glad I got her and appreciate her design more. I got her about a month before graduating and it seemed fitting for my final doll delivered at college to be one that’s similar to my major (er I guess I should start saying degree now huh 😅)! I know this was such a long post and I’m sorry for it but I figured combining my “Fun Fact” series and an observational review of her in-person would be great! Her rating still stands at a 9.7/10!

What do you guys think? Do you like her design? What’s your favorite or least favorite part? What would you change about her? Should I keep doing this series??

[mineralsrocksandfossiltalks]

Fossil Friday: Nuucichthys rhynchocephalus

Bet you've never heard of this little guy. That's because it's brand new to science! Nuucichthys was found in the Marjum Formation in Utah. It is a stem-vertebrate, which, if we recall from last month, means that it is just below vertebrate proper in the family tree.

It is characterized by a finless torpedo-shaped body that includes a snout-like anterior head bearing anterolateral eyes, approximately 25 thick myomeres, a large branchial chamber with a keel and approximately seven putative dorsal bars and a spiniform caudal process.

Curious to learn more? You can either check out the paper here:

And/or you can come to my tiktok channel on Sunday, December 8 and see a live discussion on it with me and some of my colleagues at 5pm MST.

This Sunday, December 1, my colleagues and I will be doing a discussion on the Homotherium cub found in Siberia that I talked about last week. Hope to see you there!

It will be posted on my Patreon later so if you can't make it, you can find it there!

[iamthekaijuking]

Hi Kaiju King, I knew you from UHC and liked your work! Now that Im here I wanted to ask you some things on MH and in general:

-Are you a biologist, studying or just a dedicated fan?

-What is your favorite monster?

-What do you think of some popular phylogenetic headcanons on MH like Fanged Wyverns being synapsids, Flying Wyverns being Scansoryopterygids, Banba, Duram and Kestodon and Gastodon being Pachycephalosaurids, Khezu, Gigginox, Paria and Pukei being Amphibians and Paolumu being a mammal?

-Do you like Avocados?

-And do you draw? If you do, I would like to see your work

Have a great day/night and hoping you get some more recognition 🫡

Hello there! I’m happy to answer.

- I’m not actually a biologist, I just really like biology and try and soak up anything new related to it I can find. That’s why I call myself an amateur biologist, I’m not really an authority figure and don’t have a degree. I did try to go to college to become one though, but I went when Covid hit so it didn’t work out.

- It’s kinda hard to really say what my favorite monster is because there’s a lot of things I like across many different monsters. The ones I can say are my favorites with confidence are Deviljho, Anjanath, Glavenus, Tigrex, the Raths (design wise in 5th gen), and Magnamalo (in an ironic way).

- I’m aware of some of these phylogenetic theories. I ascribe to the synapsid fanged wyvern theory for the most part myself, and with the exception of Tobi-Kadachi I think they’re all various synapsids.

Scansoriopterygid flying wyverns is a theory I used to ascribe to as well but eventually disagreed with and began to think that they and bird wyverns arose from a sister group to dromeosaurs/troodontids/aves. I actually talked about my current proposal for how that would work out in two recent posts. Another reason for that though is because I want to headcanon them as paraves, which are tied with tyrannosaurs for my favorite dinosaur family, and some recent studies propose that Scansoriopterygids might be oviraptorsaurs instead.

The various herbivorous brute wyverns being Pachyrhinosaurs is actually new to me, and I can see them being marginocephalians of some kind but maybe not pachys specifically. The herbivorous brutes have flexible tails, and pachycephalosaurs don’t because of their caudal basket. The caudal basket is basically a series of overlapping ossified tendons in the tails of pachycephalosaurs that made them very rigid. I personally have them and uragaan/radobaan as heterodontosaurs due to their diet and tusks.

Paolumu as a mammal I’ve seen float around, same with the cave wyverns being amphibians. Paria as an amphibian is new to me. Pukei as an amphibian seems pretty unlikely to me just because of the feathers, but it being related to the cave wyverns I have seen and I ascribe to it as well. My own idea is that the cave wyverns, paolumu, and pukei are a group of paravian flying wyverns that ancestrally were brood parasites with a cloaca on their tail tip to make it easier to brood parasitize and had a more muscular face and inflatable neck sacks connected to their avian respiratory system. Pukei lost the neck sacks and muscular face while paolumu lost the brood parasitism, and the cave wyverns went all in on all three (and the neck sacks are how they extend their necks).

- I don’t really like avocados that much. I’m a picky eater because of my Anosmia.

- I make a lot of art! Aside from the bones and diagrams I make for UHC’s videos I make my own original art as well (he talks about it in the end segments in his videos). I post my art here, so if you’re looking for anything just scroll down or click any tags you want to look for on my blog.

Have a good day too and thank you!

[zippers-flowers-and-wine]

So for dynamics in merfolk pods: are the Stardust Crusaders still a group? Do they start out as enemies at first before becoming friends and working together against Dio's henchmen (henchmermen?)

Yes! They’re still a pod, Kakyoin just started out as Siren-sung by Dio, but got broken out of it by the gang. Post Dio fight, the Crusaders soft-disband — Kakyoin is basically crippled due to his stomach injury from Dio, Avdol needs extensive help in feeding himself due to his hands having been bitten almost clean off, and Polnareff needs to be supported when swimming due to his caudal fin being ripped in half. Jotaro and Joseph both move on to Morioh’s coasts to meet Josuke, but rejoin the Crusader’s where they’ve settled in with Holly.

For explanation on Siren songs:

Siren songs can be broken down into 2 — sometimes 3 — groups.

Healing Songs — These songs pull from a Siren’s stamina, usually resulting in their colours becoming duller as the Song progresses. Your average siren can manage to Sing for about an hour, exceptional sirens managing to hold a Song for 6 hours and then there’s sirens like Josuke who can Sing over the course of 24 hours and still feel okay.

Coaxing Songs — These ones are the Songs of myth. Most sirens know at least a little bit of a Coaxing Song by heart, but only the most competent in them can fully wipe the mind of other individuals. Weaker Coaxing Songs are only able to lightly implant suggestions in the recipient’s mind while stronger ones are able to form full on cults.

Breaking Songs — These songs are usually only learned by particularly sadistic sirens (Ciocolatta). Breaking Songs can completely ruin someone’s mental state, making them attack themselves of those around them with fervor — with the right tweaks, a siren can make the Song’ed individual tear themselves apart.

[lecaudal]

sonic every now and then:

[phazepheonix]

i love threshers n i just read about the thresher mer george post and 🥺

now im very much a nerd for sharks so yknow how treshers have long tails. and they can theoretically use it as a weapon AND to swim very fast.

would he ever slap a human with his caudal fin? i think i read another post of dreamnap being different sea creature hybrids (unsure if it was you) he'd technically be faster than them right 🥺

(sorry i just love sharks so bad)

He was definitely very fast before the incident but never slapped anyone as he tended to stay away from humans. After the incident he couldn't balance well so couldn't swim as fast as he used to, and in his tank he may accidentally catch a diver with his tail though he feels very bad about it.

As for the dreamnap thing if they're blue ring octopus then that was me, otherwise it was another user

[moon-snailsss]

Bluntnose Six-Gill shark

Felt like I should finally make a post about my favorite shark species (They are my everything)

Basics

Bluntnose Six-Gill sharks are the largest species in their order(Hexanchiformes), with males reaching lengths of 12 feet and females reaching lengths of 18 feet! Belonging to the cow shark family (Hexanchidae), this species has remained relatively unchanged since the early Jurassic period. Their name reflects their distinctive anatomy (extra gill slits) :3

Physical characteristics

The Bluntnose Six-Gill sharks have many distinctive features, such as their streamlined, elongated body, a blunt snout, and a small dorsal fin positioned towards the back of its body. It has grayish-brown skin that helps it blend into its dark surroundings, while a pale belly provides camouflage from below (Countershading). Many people don’t think that Bluntnose sharks have dorsal fins, but that’s untrue! Unlike most sharks, they only have one dorsal fin, however it’s located more posteriorly compared to others. This adaptation is common in bottom-dwelling species as they don’t require the same level of speed as pelagic species! With a dorsal fin that’s positioned closer to the caudal fin, it enables them to make sharper turns and increases maneuverability.

Respiratory features/evolution

As we’ve previously noted, Bluntnose sharks have six gills, but why? The additional gill slit allows the Bluntnose shark to extract oxygen from the water more efficiently, which is a crucial adaptation in deep-sea environments where oxygen is scarce. Older species from the cow shark family have persistently remained unchanged, and continue to find success with a more primitive body.

Habitat

Bluntnose Six-Gill sharks are found all over the world on continental shelves, slopes, abyssal plains, seamounts, and mid ocean ridges. They reside in deep, cold waters between 200-1000 meters in temperate climates, but can be found in shallower waters in cooler climates. Scientists have primarily studied their behavior in shallower waters in high latitudes, but less is known about their behavior in deeper waters.

Migration

Bluntnose Six-Gill sharks exhibit diel vertical migration, which means they migrate vertically through the water column during the day and night. They stay in deeper depths around 600 meters during the day, and then move to shallower depths of around 200 meters during the night. Diel vertical migration isn’t uncommon among smaller marine organisms such as zooplankton, fish and squid. They travel deeper during the daytime to avoid predators, and migrate back to shallower depths at night to feed. Scientists are unsure why Bluntnose sharks exhibit this behavior, BUT I think it’s because they track the abundance of migrating prey items, as they feed on most of the smaller organisms I listed.

Diet

Bluntnose sharks feed on fish, squid, rays crustaceans, and agnathans (hagfish and sea lampreys). They also scavenge carrion and participate in feeding frenzies.

Reproduction

Bluntnose sharks reproduce through ovoviviparity. This means that the eggs hatch inside the female, where embryos develop until they’re ready to be born. Scientists believe their gestation periods last longer than two years. Litter sizes range from 20-110 pups, however it suggest that mortality rates for the pups may be high. Each pup is around 70 cm at birth.

Conservation status

The Bluntnose shark is listed as near threatened on the IUCN list. Its popularity as a sport fish makes it vulnerable to exploitation.

That’s pretty much it :3 all of this is why, you too should love the Bluntnose-Six gill shark 🦈

[yurideification]

I am not infinite;

I am biological

I possess nuclei

I am multicellular

I am heterotrophic

I respire aerobically

I am motile

I possess a post-anal tail

I possess a thyroid

I possess lepidotrichia

I possess a movable premaxilla

I possess pelvic fins

I possess an adipose fin

I have cycloid scales

I have a lateral line

I am anadromous

I possess black spots

I have a forked caudal fin

I have pink-orange flesh

I possess a silver-blue back

I have an extended freshwater juvenile phase

[akeleyselephants]

Hello World!

This is my first tumblr post! Did you know that the part of the fish right after the anal fin and right before the tail fin is called the caudal peduncle? It's a very silly sounding part of fish anatomy and it brings me great joy!