I’m trying out new layouts today to make the blog easier to navigate.

Please bear with me.

Hey there! Thanks so much for your continued patronage. To be honest, I’m surprised that anyone still reads my blog after my year long hiatus.

A lot of things happened. I graduated from my program, losing access to my lab. After my brother passed away, I moved across the country and went to China several times. Right now, I’m having a hard time finding a job related to biology, so I’m working an office job in the meantime.

But all that’s irrelevant. The primary reason I stopped posting, was that, I lost sight of where I was going with this blog.

When I originally started, I was just posting random pictures from my life, interspersed with stuff like drawings, memes…etc. My life just happened to include  a lot of morphology.  

As time went on, the blog became more and more involved and “educational”, gaining “science outreach” status and thus drawing the attention of the academic and professional community. While this is a good thing, it also prompted a certain level of professionalism and quality, which I felt like I had a hard time living up to. 

Now that my audience included not only tumblr users, but also government institutions, university professors and museum curators, etc, what do I write? How do I keep it interesting for both science professionals and general audience alike, and still have it be accessible? Should I strive for tumblr virality to reach more people, or write longer indepth articles that impart more information with less viral impact? Should I strive to educate at all? How much should I interact with the audience? Is it still appropriate to post interesting non-biology things or personal things?  

These questions (and more),have kept me silent and conflicted for the past year.  And throughout all this, I continued doing hundreds of dissections and skeletal prep, everything from chameleons, to tigers to sharks….etc.

I’m back. I don’t have any good answers, but not trying isn’t helping me. Moving forward, I’m going to try to strike a balance, between accessibility, audience, and purpose, and hopefully, I can still keep it MY blog, rather than a generalized anatomy/morphology infodump blog. 

In the end, what I really want to do, is to reveal, acknowledge, and appreciate, this hidden world, that exists inside all living things. So beautifully alien, so intimately close and so breathtaking in its ingenuity. 

Thanks again for your continued patronage…… lets go for a ride. 

- Helen (ArsAnatomica)

I always felt that photos did poor justice to the breathtaking dimensionality of skulls, so lets try something different. (Making animated gifs is something I’m somewhat new at, so bear with me here.)

This is a Gaboon Viper skull.

Gaboons are large (highly-venomous) African vipers, that hold the unique distinction of having the longest fangs in the world, with the ability to inject more venom than any other snake. There’s usually two (or more) fangs on each side. 

In the photo below, you can see a groove at the base of the foremost fangs, through which the venom duct enters the hollow fang. 

Most people think of the skull as a single bone, with a detached lower law. In reality, the skull is comprised of a number of smaller bones that fuse during development. It’s a primitive feature, whispering through the proliferation of osteoclasts, of an ancient arms race and a story of segmented bodies gliding through endless silent seas.

These days, most mammals, birds etc, have fairly solid skulls, but the further you go down in the evolutionary latter, the looser skulls become. 

Fish skulls are mostly still made up of loosely connected bones, that often breakdown into their components when cleaned for study. “Articulation” is art of making sense of it all and putting it all back together.  

This is a Cutlass fish skull. 

Cutlass fish are large eel-like fish that swim vertically, darting upwards to grab prey with their very large fangs.

Here’s a closeup of the fangs. They’re razor-sharp on the leading edge and barbed, making it difficult for prey to escape. 

Due to their inherent flexibility, snakes have very loosely joined skulls that occassionally require assembly. 

This is an eastern diamondback rattlesnake. 

The skull of a Bengal tiger rests along side the skull of a domestic cat.

Notice the proportionally smaller braincase and eyes in the tiger, and the much larger flanges for muscle attachment, in comparison to the overall size of the skull.

As animals scale up in size, more muscle is needed to bear the additional weight and counteract the effects of gravity. To anchor the increased mass of the muscle, bones become more robust. Thicker, heavier, with larger flanges, and deeper hollows to provide the additional muscle with leverage. 

It’s a cyclic system. More muscle is needed to support heavier bone which in turn supports more muscle…etc. 

You’d think it could go on forever, but as animals become larger and more powerful, they also become heavier. For land predators, the cycle reaches a cutoff size when the increasing weight begins to negatively affect agility, maneuverability, and the ability to successfully catch prey. 

Anonymous asked: Thanks for the fascinating blog, although I can't quite fathom the thought processes that lead to manually collecting roadkill skunk juice. Made for a compelling read though, especially with those excellent diagrams.

Hey there, thanks for reading my blog. 

I have to say that it was largely curiosity driven.

What did the spray look like? How did the glands work? Anal glands in most mammals are not muscular, so what powers the discharge of the spray? Skunks are such common-place animals, but they’ve got this adaptation that’s really quite unique and bizarrre. 

The spray is incredibly volatile and diffuses into the air really easily, but smell-wise, it could be worse. I took a sculpture class once and used sulfur-based plasticine (a type of clay). It smelled just like that. It’s strong, but not really intolerable. 

…. and yes, the practical joke potential of this did cross my mind, but I never did anything with it since it was too hard to store, and would permeate any container. 

While looking at the little screech owl, I took a series of photographs and made this gif to illustrate the of the automatic grasping action of the talons.

The structure of bird feet is set up so that the foot automatically grasps when the ankle joint is bent.  

This automatic grip allow birds to sleep while perching, and for raptors clench/grasp prey as the leg is folded on impact.

The mechanism of the foot is ingenious…. there’s no muscle in there at all. 

The foot is powered entirely by a pulley system of tendons. 

Two tendons that run along the back of the leg, Flexor Digitorum Longus and Flexor Hallucis Longus are responsible for the automatic grasp. The former pulls the forward facing toes, and the latter pulls on the hallux, or back toe. 

I drew a schematic diagram of these two tendons here:

It’s particularly interesting in raptors.

Raptors swoop down on prey with talons/legs outstretched. The impact with the prey folds the raptor’s legs against its body, causing the talons to clench automatically, tearing into the prey. The automatic grip is strong enough to kill, and is what allows many hawk species to catch and kill other birds in midair. 

The ingenuity and perfection of this mechanism is mind-blowing.

Isn’t he cute? He looks almost alive. 

Unfortunately, he’s not.

This little guy is an eastern screech owl. Following a heavy storm, he was found dead on a residential street, entangled in some fallen branches at the base of a utility pole. 

I’ve previously posted a picture of him before.  I’ve never had the opportunity to look at owls close up.

He’s recently dead, his eyes have not yet begun to cloud or dessicate. Owl eyeballs are not spherical, they’re bell shaped, and fixed in their sockets. 

Since the eyes are fixed, owls move the entire head instead and can turn it almost all the way around.

There’s another lesser known effect of eye immobility. Owls have excellent vision but have close range astigmatism. The area just in front of them is always blurry. 

But that’s okay, because that blind spot is covered by crines. Crines are specialized whisker-like feathers around the beak area that extend into the blurry zone. 

These whiskers are highly sensitive, and allow the owl to “feel” for it’s food items, since it cannot see them. 

The owl’s capacity for silent flight comes from the fimbriate border of it’s flight feathers. This comb-like edge breaks up turbulence over the wing to reduce sound. 

These nubbins on his talons are called spicules, and are modified scales. Theyre common in birds of prey, and help improve grip by increasing the surface area, the same way fingerprints function in humans. 

Owing to the circumstances in which he was found, we initially believed him to be another unfortunate motor vehicle victim, but soon realized that this was not the case. 

There’s two blackened spots at the tips of his talons. 

His underside is a charred mass of feathers, and he’s got a faint “burnt” smell. The skin on the inside of his leg is roasted to a golden brown. The word “rotisserie” comes to mind.

I guess that power line wasn’t a safe perch after all. 

Can’t pass up the opportunity to make some more drawings.

A while ago, I was asked create a series of fact cards for Zoo Kingdom, a facebook game made by Blue Fang Games, the makers of Zoo Tycoon. 

Each species introduced in the game, had a series of fact cards that aimed to introduce some aspects of their natural history, morphology and ecology. 

I made about 150 of these. Below are my personal favorites. 

I haven’t updated in a while. I’m very sorry. 

I would like to offer my gratitude to everyone who as taken the time to inform me of their interest in my blog. I’m deeply grateful for your support, and am elated to see so much interest in morphology. 

Unfortunately, It’s been very difficult to keep up with the volume of correspondence I receive. I’m sorry I haven’t replied to all of your letters.

Many of the letters I receive often contain similar questions, so I’d like to take the time now to address these recurrent concerns. 

Do you kill these animals or are they already dead when find them?

No, all of the specimens are collected from natural deaths, donated or already part of the collection. Necropsy is rather interesting. Whenever possible, I try to determine cause of death. Etched in each bone and woven into the fibers of each muscle is the life and death of the individual. 

 It’s a story that deserves to be told. 

How do you go about bleaching clean bones? 

“How to bleach?” is by far, the single most common question I encounter. There is no single answer and everyone has different techniques. Personally I use non-chlorine bleach. It is a concentrated Hydrogen Peroxide solution, and is available at most grocery stores.

The concentration depends on the delicacy of the specimen. I use it straight for larger, more robust things such as deer. For smaller, more delicate specimens like birds, I dilute it with water and monitor closely to avoid over bleaching. 

During bleaching, I take out the bones once in a while, and wash and dry them to check. You can always continue to bleach if the bones are not sufficiently clean, but over bleaching will damage bone.

Will you send me some reference photos of a specimen?

Yes, but I get a lot of requests for photos, so it might take a while. Please limit requests for photos to about 5 per request. Be specific about what you want and I’ll check if I have anything that suits your needs.

Is your blog named after a quote? 

No. Ars Anatomica is Latin for “The Art of Anatomy.” 

What do you do with the skeletons you clean most of the time?

It varies. I’m often asked to clean stuff for various departments and faculty at the college. These specimens (often rare and cool stuff,) are cleaned per departmental specifications and returned. Specimens that belong to me personally are kept. I may try to mount them depending on condition. Animals collected from roadkill often have large scale bone shattering in the skull, vertebral column or rib cage and pelvis areas. These types of shattering injuries are difficult to repair, making many of these skeletons unmountable. If I have a spare pelvis lying around I’ll try to swap it out. 

Most of the time. I just enjoy looking at them. Bones read like good books.  

What did you study/ major in?

I majored in art and biology. For the art aspect, I focused on illustration. For biology, I focused on tetrapod morphology.

The pregnant doe that you posted about is the worst thing I have ever seen. How can people be so cruel?

I get a decent amount of mail about that post. As tragic as this accident was, I don’t think it was avoidable. She was killed in the wee hours of the morning, on an unlit highway that was heavily wooded on both sides. The speed limit was 75mph. 

It’s awful, but I can’t think of any way that this accident could have been averted. The doe and the driver were both at the wrong place at the wrong time. 

I’m a biology student. How do I learn to draw anatomical diagrams?

I’m not sure that I can offer any advice beyond the importance of general practice. It’s true that I draw a lot of anatomical diagrams, but I also enjoy drawing a large variety of random things. I think every little bit of practice helps. Even if you want to draw diagrams, it’s important to not confine yourself to drawing only diagrams. 

Apologies for the delay and thanks again for your interest and support. 

For viewers with specific concerns, data, literature and photo requests. Please accept my apologies.  I’m slowly working through them. 

Making sketches of an Eastern Screech-Owl …a sad power line fatality.

To use him to educate others, is the least we can do. 

He’s a magnificent little creature.

Making sketches of a shortnose gar. These guys have very interesting jaw structure. 

Taking apart the baby skunk.

In the interests of length, this entry is mostly about internal organs.

All images are linked to high res versions, click to view.

NOTE: This post contains graphic images of an animal being skinned and photos of internal organs. It is NSFW and R-18G. Click “Read more” if you wish to see it. 

Read More

This baby skunk was picked up yesterday.

His teeth are perfect and show no wear. 

Elongated front claws for digging. 

He’s very small

This poor little guy is just a baby. He’s only the size of a squirrel and probably less than two months old. Just like the fawn, he was probably crossing the street with mom when he was hit. He’s still on his first coat of soft baby fur.  

While winter seems to have the greatest number of roadkill as animals disperse. Spring and early summer are sadly a time that a lot of babies die. Depressingly, the speed limit for the road was only 15mph.