The Osteology of Decorative Plastic Halloween Skeletons, Part 10: The Owl

I finish this year’s set of Halloween skeleton posts with the owl (available for $19.49 at Target), which contains a unique and compelling mix of mistakes.  

As with other fake bird skeletons, this one has bones where the tail and wing feathers should be.   

And the sternum (which connects the ribs at the front of the body) looks much like the sternum of a human being, and not at all like the deeply-keeled avian sternum.  

But the biggest issue is the presence of ears.  Certain kinds of owls do have tufts of feathers on top of their heads which superficially resemble ears, but these tufts are not anatomically associated with the internal ear, and are not involved with the sense of hearing.  And even if owls did have external ears in the manner of mammals, mammalian external ears are cartilaginous, and not part of the bony structure of the skull, a mistake common to fake Halloween skeletons of various mammals.  Thus we see a compounded double error of confusing feather tufts with mammalian ears, and presenting mammalian ears as bony projections from the skull.

The Osteology of Decorative Plastic Halloween Skeletons, Part 9: Snakes

It is interesting to note that all tetrapods (the land vertebrates, i. e. amphibians, reptiles, birds, and mammals) have essentially the same skeleton.  The bones vary in size and shape between species, but whether it’s a salamander, an armadillo, or a condor, the basic skeletal elements are mostly the same.  The biggest potential variation is that some elements can be lost due to evolution.  Snakes (which are, evolutionarily speaking, a highly successful group of legless lizards) are an extreme case, lacking almost everything except the skull and the vertebrae and associated ribs.  (There is also a hyoid bone and, in a few species, tiny remnant hind limbs.)

There are numerous plastic snake skeletons available.  

This one (available at Amazon for $14.94) lacks ribs entirely.  

This other one (available at Target for $12.60) has ribs, although they are not exactly realistic.  

In both of the above cases, the skull is much too massive and lizard-like, unlike the highly specialized, and generally weird, skulls of actual snakes.  

There is even this two-headed skeleton, which was once available at Spirit Halloween.  It suffers the previously observed problems of lacking ribs and having an unsnakish skull.  But two-headedness is indeed a real phenomenon in snakes and other reptiles.  It has been known to occur in the squamates (the lizard and snake group), the turtles, and even Hyphalosaurus, a Cretaceous choristoderan, but as far as I know there are no examples from the archosaurs (crocodilians, pterosaurs, dinosaurs, and birds).

The Osteology of Decorative Plastic Halloween Skeletons, Part 8: The Octopus

I have addressed the matter of Halloween skeletons for invertebrates before with a post about a spider “skeleton” in 2017.  (There is also a scorpion “skeleton” available.)  But I felt that I had to take note of this octopus “skeleton” (available for $14.99 at Spirit Halloween), because it takes the fake invertebrate skeleton concept to new heights of ridiculousness.  A spider at least has a rigid exoskeleton, which might lead someone to think that it has a bony internal skeleton.  But doesn’t pretty much everyone know that an octopus has no virtually hard parts?

Introducing a New Year of Halloween Skeletons

The Halloween season is here again, the time of year when it feels as if there should be some cool adventure to be had.  I don’t know exactly what it would be.  A full zombie apocalypse might be too much to ask, but something should happen.  And of course it never does.   

Also it is the spooky time of year when the days are overtaken by darkness, and I am again inspired to undertake my unrealized dream of writing fiction, particularly some sort of fantastical horror.  And sometimes I’ll get an idea, or even start to write something, but it never works out, because I lack storytelling ability.      

And again I find myself critiquing the scientific accuracy of fake animal skeletons used as Halloween decorations.  On would think that after two years and seven installments, I would run out of material.  But I keep finding more (mostly) wonky skeletons.  Using fake skeletons, both human and animal, in Halloween decorating has become a huge trend; indeed, in 2017, the year in which I started this series, the Wall Street Journal had an article on the popularity of such decorative skeletons. 

Here are links for the series from the past two years:

The Home Depot Tyrannosaurus

The Raven

Assorted Mammals

The, Um, Spider

The Home Depot Triceratops

The Bat

Frogs

The Graveyard of Decorative Plastic Halloween Skeletons (not technically part of the series, but related)

The Graveyard of Decorative Plastic Halloween Skeletons

Regular readers of this blog (by which I mean my family members and close personal friends) will be aware of my one-man crusade to expose the scientific inaccuracies of decorative plastic Halloween skeletons to the world (by which I mean my family members and close personal friends).

The weekend before Halloween, I was walking around town looking at the decorations, and I came upon this display.  It contained almost every plastic animal skeleton of which I had previously been aware, and some that I had never seen before, letting me know that there is more material out there should I wish to continue the series for a third year.

The Osteology of Decorative Plastic Halloween Skeletons, Part 7: Frogs

The frog is not an animal which one normally associates with Halloween.  Two different styles are available, however, the first for £3.95 from Mad About Horror.  (It’s also available in the United States, but Mad About Horror had the best picture.)

Whoever designed this skeleton actually did a good job with it.  It has no glaring mistakes, and it even does a nice job depicting a frog’s unusual pelvic structure.  I examined one in a store, and found that it had no lower jaw, but I see that as more of an omission than an outright error.

I cannot, though, give the same praise to this second style of frog skeleton, available for $6.99 from HalloweenCostumes.com.  It shows the frog with a rib cage, which frogs do not have (as one can tell from the first skeleton).

The Osteology of Decorative Plastic Halloween Skeletons, Part 6: The Bat

  Bats are a characteristic animal of Halloween, such that rendering one as a skeleton to make it scarier seems unnecessary, even redundant.  Yet we have the bat skeleton, available for $31.45 from DHgate.

It has external ears presented as bony elements of the skull, which is a common problem with plastic Halloween mammal skeletons.  

What’s even stranger is the depiction of the bones that make up the wings.  A real bat has one digit in each wing that is outside the wing membrane, and four more digits that support the wing membrane. This fake bat has only three digits in position to support the wing membrane.  And the metacarpal of the uppermost wing digit has been replaced with what are apparently meant to be a radius and ulna.  (That’s the weird double bone along the top of the wing in the plastic skeleton).  In reality the radius and ulna are part of the arm, and thus closer to the body, although in bats the ulna is greatly reduced.

If you find all of this confusingly technical, you can check out correct bat skeletal structure here. 

The Osteology of Decorative Plastic Halloween Skeletons, Part 4: The, Um, Spider

For our final installment, we have the Halloween spider skeleton, available for $20.99 from Target.  

I don’t know if I even need to say this, but . . . SPIDERS ARE INVERTEBRATES!!!  THEY DON”T HAVE SKELETONS!!!!! 

My series is at an end.  And, as I said earlier, maybe it is wrong for me to provide osteological criticism of plastic Halloween skeletons.  And maybe that is why I don’t getting invited to Halloween parties.  Or maybe it is because none of my friends ever have Halloween parties.  

In any event, I feel better.

The Osteology of Decorative Plastic Halloween Skeletons, Part 3: Assorted Mammals

Next in our series, we have what first inspired me to write the series.

There is the cat skeleton, available for for $25.59 at Amazon (and eligible for Amazon Prime).  

There is the dog skeleton, available for $15 from Target.

And there is even the rat skeleton, available for $8.99 from Jo-Ann Fabric and Craft Stores.  

And there are many more examples of plastic skeletons for each of these mammals, and I could probably find other types of mammals with the same problem if I looked.  

In case you haven’t noticed, I will point out that all of these skeletal animals have external ears. And the external ears are shown as bony elements projecting from the skull.  External ears are cartilaginous.  They are not part of the bony structure of the skull.  

(Perhaps the designers think that the skeletons would be unidentifiable to the general public without an appropriate set of ears.  Years ago I volunteered at a museum that had a horse skeleton mounted in the center of the main exhibit area.  Visitors frequently assumed that it was a dinosaur.) 

I guess that I should be glad that external ears aren’t added to human Halloween skeletons (as far as I’ve seen).  

The Osteology of Decorative Plastic Halloween Skeletons, Part 2: The Raven

Moving on to living species, but staying in the theropods, we come to the subject of our second installment, a (supposed) raven skeleton, available for $7.99 at Party City (and elsewhere). 

Noticeably weird is the fact that the ribcage is completely open in front, with no sternum to connect the ribs.  

But, even more weirdly, whoever designed this skeleton seems to have been under the impression that birds have bones in their feathers.  In the areas corresponding to the flight feathers of the wings and tail, there are elongate rows of bones similar in appearance to the fingers that support a bat’s membranous wings.  (Birds do have remnant finger bones in their wings, but they very small and do not parallel the flight feathers.)

The Osteology of Decorative Plastic Halloween Skeletons, Part 1: The Home Depot Tyrannosaurus

We are deep into October, and the Halloween craziness has begun.  Perhaps you do not like the Halloween craziness, but consider this—the Halloween craziness may be the only thing that prevents the Christmas craziness from starting in September.  I am fascinated by the Halloween craziness, because I remember the time before Halloween consumed the entirety of October.  One topic that I find particularly interesting is the wild profusion of yard decorations now available. (During my childhood, it was a jack-o’lantern or nothing.)

One type of yard decoration that I seem to be seeing more and more is the plastic animal skeleton.  A variety of animals are represented, but in all cases something in wrong with the morphology of the skeleton on a very basic level.  Thus I am beginning a multi-part series of blog posts that will examine decorative plastic Halloween skeletons from a zoological/paleontological, and, more specifically, osteological perspective.   

Maybe it is wrong for me to scientifically critique Halloween decorations.  Maybe I should put aside my criticisms and blind myself to everything but the fun of the season.  But I can’t help it.  Errors bother me.  (I am someone who is annoyed when people describe food as “healthy” rather than “healthful”.)

The subject of our first installment is a Tyrannosaurus rex skeleton (with LED illuminated eyes) available for $299 from Home Depot.

There are a lot of inaccuracies here, including the head being too large for the body, the almost-nonexistent pelvic bones, and, well, the LED illuminated eyes.  But what really gets to me is that the forelimbs have three digits.  As anyone with a basic knowledge of dinosaurs knows, having only two fingers per hand is a defining characteristic of the tyrannosaurs.  

One for the Taphonomically Inclined

(Click the image for a larger version.)

About ten days ago I found this dead hawk.  I think that it is a Red-shouldered Hawk (Buteo lineatus), but hawk identification is not one of my strong points. It was lying on a nearly vertical stream bank, about a foot above the waterline.  

It had been lying in this position long enough for several twigs to accumulate on it, without having been disturbed by scavengers.  The feathers were still in a configuration which was nearly perfectly life-like. At the same time, what appear to be the neck vertebrae were exposed, indicating that the hawk's soft tissues had been removed, presumably by the action of insect larvae.

The hawk reminds me somewhat of Archaeopteryx specimens with preserved feathers.  It is interesting to consider the length of time that the hawk's feathers and skeletal structure had remained undisturbed, and how this would affect the potential for long-term preservation, in the rare event that such a dead bird would eventually be covered by sediment.    

Roll the Bones

I went to the dentist on Tuesday. He said that I have the jawbone of a fifteen-year-old. Apparently, as one gets older, the bone structure of one's jaws degrades significantly. But the bone structure of my jaws has not degraded, for whatever reason.

The condition of my bones is not newsworthy in and of itself. What stands out to me is that if I say I have the jawbone of a fifteen-year-old, it sounds as if I buried the other parts in the woods.