Friday Troglobite

Troglobites are animals that live in caves, and generally, they rule. I'm going to attempt to post a picture of a new cool troglobite every Friday. Today's is a Psuedoscorpion discovered in an Australian cave. Psuedoscorpions are arachnids, and evolutionary cousins to the scorpions. Unlike scorpions, they deliver venom via their claws. To really see the the arachnid family (~class~) resemblance, you have to look at the jaws of Wind Spiders (Solifugae). I've posted a picture of one below.

New Psuedoscorpion, pretty scary for a 3.5 millimeter creature.

Solifugae. The jaws of both arachnids are large and scissor-shaped.

Images from:
http://ngm.nationalgeographic.com/2007/09/new-troglobites/liittschwager-photography
http://farm4.static.flickr.com/3326/3437390672_ce0b3817b6.jpg

Raccoon....Dog

As soon as I saw the Raccoon Dog (Nyctereutes procyonoides) I checked to see if they were available as pets. These primitive dogs live in rural Japan, Korea, and China. They are one of only two Canids to be able to climb trees, the other one being the Gray Fox. And, it's the only dog capable of hibernating during the winter.

The raccoon dog is monogamous and prefers to run away or scream if danger approaches. Raccoon Dogs have become the focus of groups against fur trade. The (this link is not for the squeamish) reality of the situation seems to be grim. In a weird twist, the Raccoon Dog is considered an invasive pest in several European countries. The video below is pretty entertaining.


Images from:
http://scienceblogs.com/zooillogix/raccoon%20dog%201a.JPG
http://retrieverman.wordpress.com/2009/02/24/the-tanuki-marderhund-or-raccoon-dog/

The Goblin Shark is Ugly

I'm not too familiar with Goblin lore, but they must be formidably ugly  for Mitsukurina owstoni to be named after them.

The Goblin Shark is only this ugly when it has its jaws protruded. Usually it looks more like the specimen in the video, which likely died soon after being placed in an aquarium. These are deep water creatures (may never encounter light during its lifetime) which grow up to 11 feet long. That nose is filled with electrosensors that it uses to find prey...although probably a generalist, we aren't quite sure what they are feeding on.


The long heterocercal tail is incredible, I have no idea what the siphon-like openings on the side of the head are used for, and I'm really surprised it has such big eyes.

Image from:
http://www.greengoblin.com/internal/corner/shark.html

Mymaridae (Fairy Wasps)

Fairy Wasps are quite possibly the smallest insects to have ever existed. Male fairy wasps live out their entire life cycles where their mother oviposited them, trapped inside a water beetle egg with their sisters. Inbreeding is the norm. For this species it's almost becoming ridiculous to have males at all (this one doesn't). How the fairy wasp gets away with all this inbreeding is currently unknown. One popular idea is that a beneficial complex of genes exists that would be scrambled by the process of random mating...which may or may not be right.

Giant Jellyfish

Check this out:

Wow. Only two jellyfish in the world get this big, Nomura's Jellyfish of Japan (Nemopilema nomurai) and the Lion's Mane Jellyfish found in Arctic and Australian waters (Cyanea spp?). 'Spp' stands for species plural; because of size and color variation across its range the Lion's Mane is not known to be a single species. I'm pretty sure the above image is of Nemopilemna nomurai. The Lion's Mane (which is the larger of the two) has a bell divided into eight lobes as seen below. 

If you define 'plankton' as pelagic sea creatures whose movement is largely guided by the currents, these are the largest plankton is the world! The record holding Lion's Mane specimen had 120 ft tentacles, longer than a Blue Whale. Still, they have to worry about jellyfish predators like the equally massive and comically proportioned Ocean Sunfish (Mola mola).

Images from:

http://www.kirainet.com/english/

http://www.marlin.ac.uk/phylumdetails.php?phylum=2353

http://www.mola.org/mola/molamola.gif

Brownsnout Spookfish

For as much variation exists, it's rare to find a new major morphology. Thankfully, the Brownsnout Spookfish (more fun to say than Dolichopteryx longipes) has appeared to entertain us with new evolutionary innovation.

Lateral view isn't his best angle. It doesn't show his incredible eyes (which are divided into up and down facing pupils, effectively giving it four eyes, and that's not even the cool part! Take that Anableps). The cool part is that the Brownsnout Spookfish is the only vertebrate to use a mirror to make an image in its eye. The top corneal opening of each eye is focused by the a mirror made of layers of reflective plates of guanine crystals. The bottom facing pupil is still focused by a lens as in 'primitive-eyed' vertebrates like us. It's cool to see a new biological technology developing in and independently contributing to an existing visual system.

Apparently it also has a crazy anal fin.

Images From:
http://nature-phenomena.blogspot.com/2008/05/deep-sea-brownsnout-spookfish.html
http://news.bbc.co.uk/2/hi/7815540.stm
http://en.wikipedia.org/wiki/File:Dolichopteryx_longipes.jpg

"The most mysterious, the least known of all dogs"

Speothos venaticus is the least understood dog on the planet. I had no idea it existed before seeing it in The Life of Mammals. Known as the Bush Dog, or locally (Amazonia) as the Vinegar Dog, this is the only Canid with webbed feet. Why would a dog have webbed feet?

These dog are semi-aquatic(!) and hunt rodents and other small animals, occasionally diving to catch them. Bush dogs tend to be found in packs of 10-12, but occasionally appear solitary. They have a unique dentition (not surprising for such a derived species) that seems to emphasize ripping and tearing ability. You can view an excellent scan of a Bush Dog skull at one of my new favorite websites.  Bush dogs were discovered as fossils in caves before live specimens were known to science. Speothos are still considered extremely rare across their range, which is not well defined.

David Attenborough once again provides the world with an excellent view of a rare animal.

New biology term.

     Every once in a while (all the time...) I do a random google search to look for cool new stories. Just now I searched "Subterranean Coleoptera". The first result was a recent paper:  Evolution of Subterranean Diving Beetles (Dytiscidae: Bidessini) in the Arid Zone of Australia. 

     I won't go into the details of the paper, but I did learn a new word......Stygobiontic. If you google search define:stygobiontic you'll be utterly disappointed. I finally found the definition in a powerpoint presentation by a researcher who studies stygobiontic species in Texas.

     Stygobiontic species live only in groundwater, they are almost never found at the surface. Cool.

     Below is a drawing from the paper mentioned above, by Remko Leys et al. For comparison I put a 'standard' member of the family below.

Standard Dytiscidae from bugguide.

Artificial selection, natural selection, both?...or neither

You might notice something peculiar about Heikea japonica.

In his 1980 documentary series Cosmos, Carl Sagan (who was absolutely brilliant) used this species as an example of evolution by artificial selection. Thomas Henry Huxley, one of Charles Darwin's greatest advocates, apparently did the same. The two claimed that Japanese fisherman tossed back crabs that had human, or more specifically, samurai-like faces. Over time this selection pressure led the entire population to this phenotype. It's really a very cool example, but also contentious. Here's another picture:

As a side note: personally, I'm not a fan of 'artificial selection' in this case; is any selection pressure exhibited by humans on another species artificial? Where do we draw the line, perhaps domestication? But that's a different and perhaps more boring semantic conversation. Here's a giant Japanese spider crab (nearly 13 foot leg span!) to bring you back.

Joel Martin argues in 'The Samurai Crab'  that only natural selection played a part in shaping this animal's appearance. He points out that the contours on the crab carapace are indications of internal muscle attachment points(apodemes), which is useful information, but not nearly as useful as I think he thinks it is.

Martin's strongest claim is that the crabs, not more than 1.5 inches across, were too small to be eaten.  He also cites other species which show human/samurai-esque faces (pictures below), some of which live in the same waters off of Japan as H. japonica. These other species are so similar that locals don't differentiate between them. Perhaps all of the crabs in the region experienced similar human induced selection?

The jury is still out on this one; proponents of the Sagan/Huxley version say that villagers would have eaten these crabs historically, especially before mass-fishing practices became popular. Also, just because other species exhibit similar characteristics does not mean selection didn't occur to put the finishing touches on the modern H. japonica appearance. I submit that eye/mouth mimicking shapes occur often in nature to scare off visually guided predators, perhaps another reason for the face shape on this intriguing crustacean.

References:
Pictures 1 and 4 comes from The Samurai Crab, linked above.
The giant crab comes from wikipedia.
Picture two can be found here.

Two Times the Telson

I found this image in a research note published in the Journal of Arachnology (1995 23:199-201).

Something weird must have happened developmentally to cause these individuals to have two tails/stingers (metasoma/telson). Vachon believes the anomaly to be a case of incomplete twinning. Apparently this mutation was known in ancient times, because Pliny, citing Aelian (alien?), placed the two-tailed scorpions in their own class(Vachon 1953).  Modern literature does not describe these beasts until Pavesi in 1881. Since then two-tailed specimens have been described in at least 9 species of scorpion. I've heard at one point the two-tailed specimens were considered a completely different species, though this could be a misinterpretation of the point made earlier. Certainly a curiosity I'd rather not be stung/stung by.

Tarsus Replacing Mite

I couldn't sit on this one any longer. I was trying to save it for a slow day...but it's too cool. This mite, Macrocheles rettenmeyeri, is named after recently deceased ant expert Carl Rettenmeyer. M. rettenmeyeri is only found plugged into the distal end of army ant legs, where it effectively replaces their 'claws', or more insect specific, the tarsus. We think it feeds off of army ant hemolymph (blood). The best part is that it functionally replaces the army ant claws! This means that the tongue replacing isopod is not the only species known to "functionally replace a host organ". I'd like to think that in army ant bivouacs (temporary shelters constructed out of their own bodies) ants may be connected to mites, connected to mites, connected to ants. Anyways, on to the picture (courtesy of a Carl Rettenmeyer poster):

The army ant bivouac link is actually a sculpture, by Jill Moger in the UK.

Speaking of Hummingbirds...

Another spectacular short clip from David Attenborough's, The Life of Birds. He really nails the finish on this one. Also, 9000 Hummingbirds a day, count me in!

Monday Morning Moonwalk.

I never met Dr. Kim Bostwick while at Cornell, but if I had I definitely would have asked her to do her impression of this crazy bird doing the moonwalk.

P.S. These birds create a sound by slamming specialized wing feathers together 80 times per second, apparently faster than a hummingbird wing beat.

Pterosaur Tooth

This morning I woke up to a very exciting email from ebay informing me that I had won this 33mm fossilized tooth from Siroccopteryx moroccoensis, a Pterosaur.

Pterosaurs, commonly known as Pterodactyls,  are one of my favorite extinct lineages. They were the first vertebrates to evolve powered flight. Funnily enough, when Cosimo Collini discovered the first fossils in 1784, he thought they were aquatic creatures who used their giant front limbs as paddles.

Unlike birds, who are thought to have gotten their start by climbing trees, Pterosaurs appear to have gone from the ground up. This is based on the lack of tree-climbing adaptations in early Pterosaurs...however their exact origins are still up for debate.

Recently Michael Habib of Johns Hopkins has revealed that Pterosaurs took flight by running on all fours, making them top contenders with the giraffe for the doofiest looking animal while running award. Dr. Habib also attempts to dispel the interpretation of Pterosaurs as, "very skinny, almost emaciated-looking things, basically a hang glider with teeth." Turns out they were actually pretty ripped.

Pterosaurs living 220 million years ago were generally small, with wingspans of approximately 10 inches. As their history progresses the smaller lineages seem to have disappeared. Some authors think this was due to competition with early birds, 100% arm waving (no pun intended). By the time they went extinct 65.5 million years ago, two genera (one of them toothless, weird right?) had nearly reached the 40 foot wingspan mark, making them the largest flying animals ever known. Siroccopteryx moroccoensis had a wingspan of about 20 feet...not too shabby.

You can learn a ton about the Pterosaurs from Wikipedia: http://en.wikipedia.org/wiki/Pterosaur

Pterosaur/Giraffe image from: http://news.nationalgeographic.com/news/2009/01/090107-pterosaur-picture.html

Pure awesome.

A Termitophilic Staphylinid. So cool it hurts.      Awesome is an overused word. That's why I reserve 'pure awesome' for beasts that really defy imagination. There's no question that Thyreoxenus brevitibialis fits the bill. This bug is totally out of control. For reference, here is a pretty standard Rove beetle.
      The image comes from Taro over at Myrmecoid. I owe Taro for my appreciation of evolution (and a lot of the examples I post here). Taro's an entomological genius (seen here collecting from 'non-personal feces'), so make sure you click on over to his blog. I'll let him give you the low down on this Staphylinid:

      This amazing staphylinid belongs to the aleocharine tribe Corotocini. The corotocines are mainly termite guests. Many exhibit extreme morphologies where most of the body is fleshy and blobby, like this Thyreoxenus species. Although this image is in lateral view, when viewed from above, some of these corotocines (including Thyreoxenus brevitibialis) closely resemble termites.
      Even Richard Dawkins has acknowledged the awesomeness of corotocines in his book Climbing Mount Improbable by stating that Coatonachthodes ovambolandicus is “one of the most astonishing spectacles in all natural history.”

Nanorchestes antarcticus

Macromite is one of my absolute favorite blogs. The colored SEMs, very labor intensive pieces of art, are beyond belief. And it turns out that mites are equally as diverse as insects (if not more so), with all kinds of crazy evolutionary stories. From Macromite-

"Herds of hundreds of thousands of these mites roam parts of the Antarctic continent, presumably grazing on algae"

If you ever make it to Antarctica, make sure to keep an eye out for a herd of these .1mm marvels.

The Aquatic Ape Hypothesis.

Every time I bring up the Aquatic Ape Hypothesis people laugh. They think it's ridiculous. To me, it makes total sense. Our loss of body hair is similar to other mammals with aquatic ancestors, i.e. the elephant and rhinoceros. Human baby fat, our ability to control breathing, and that bit of vestigial webbing between your fingers all make sense in light of the AAH. It's certainly an idea worth investigating. Unfortunately, leading anthropologists have been laughing since the AAH was proposed in 1942. Check out the videos below and see what you think. The first is incredible footage of chimps wading (90% of chimp movement in water is bipedal). The second is a 15 minute lecture (highly recommended!) by the leading proponent of the AAH. Below the videos is a link to a short thesis on the subject.

What really bothers me is that the discovers of Ardipithecus are blabbering on about how human-like the fossil is, which is unexpected only if you think about evolution strictly from a gradualist perspective and believe in the molecular clock that dates the human-chimp divergence to about 7 million years ago. Meanwhile they should be science-gasming over their own discovery that, "a mosaic of woodland and grasslands with lakes, swamps and springs nearby" was this beast's habitat.


Watch Chimps wading through water on two feet.wmv in Educational  |  View More Free Videos Online at Veoh.com

If you haven't been on Ted.com, you need to go!




http://www.riverapes.com/Me/Work/BipedalismThesis.htm
(what an unfortunate URL...)

Do you know about the Honeyguide?

David Attenborough gives you the low down in 3 minutes:

What's this? It's Paussinae.

This is Platyrhopalopsis, a Carabid (ground beetle) from Thailand. Those radar dishes on the top of its head are the antenna.

Although the exact host is unknown, this beetle almost certainly lives in an ant nest. This lifestyle is known as myrmecophily, and you wouldn't believe all the crazy species that make a living this way. Paussinae may be using those antenna to communicate with their ant hosts, but beetles in this group are generally collected only at light traps; so most of their natural history remains a mystery. Some researchers have reported ants using the antenna as handles to relocate the beetles. The plate below shows the astounding diversity of antenal morphology in the subfamily. It's a great example of 19th century naturalist drawing, by John Obadiah Westwood, 1837. 

Primitive Paussinae generally have standard mouthparts and thick exoskeletons, while more derived species are lighter and have spoon shaped mouthparts specially adapted to receive regurgitated food directly from ants. All members of the group can mix quinones and gases to produce an explosive self defense, evolutionarily independent of but extremely similar to the famous Bombardier beetles, a different lineage of the Carabidae.

References:

http://commons.wikimedia.org/wiki/Category:Paussinae

http://entomology.lsu.edu/lsam/inquilines/Coleopterainquilines.htm

http://www.biodiversityexplorer.org/beetles/carabidae/paussinae/index.htm

APB: New Species

This Aphodiine has got to be the coolest dung beetle I've ever seen. The sculptured exoskeleton is very unique. And what's with the double horns? All I know is that it's from peninsular Malaysia and will be named Rhinocerotopsis nakasei.  A 'typical' North American Aphodiinae is shown below. Look for the family resemblance in the shape of the head.



References:
Maruyama (2009) Rhinocerotopsis nakasei (Coleoptera, Scarabaeidae, Aphodiinae), a new genus and species of Stereomerini from Peninsular Malaysia. Esakia, in press.


The great picture of the new species came from a Japanese naturalist's blog Taro introduced me to: http://d.hatena.ne.jp/dantyutei/

The typical beetle comes from Bug Guide. http://bugguide.net/node/view/355100/bgimage