FOSSIL CRATES

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Meet the longest, heaviest crab! The Japanese spider crab, #Macrocheira kaempferi, is one of my favorite arthropods. I saw my first one at th Paris Natural History Museum in 1998 and was stunned. I had no idea they grew so huge! These are all at the supercool Art Zoo Museum in Amsterdam, Netherlands. Tis the largest living arthropod with a “leg span” of 12 ‘ claw to claw, and males exceeding 40 lbs. Amazingly, the body is 16” in diameter, think spiny car steering wheel, coat hanger, or large pizza box, the rest of the body being 8 walking legs and 2 feeding claws. It lives in the Pacific of Japan, at 150 -2000’ deep, in ~50 degrees temp. Tis a slow scavenger striding soft sediment, feeding on dead fish, mollusks, and algae. They love whale falls with a lone big whale feeding a community for decades. I had no idea young crabs decorate their shells with sponges and algae for camouflage. They cease doing this as adults, likely because their immense size makes them immune to most predation. Males grow “outsized claws” we all love while female claws stay smaller. Despite the fearsome size, tis docile, though if I saw one while diving I’d be nervous :-). Why the long claws? Isn’t it dark at those depths? Don’t they out-reach their vision? How sensitive are the claws to touch? So many questions I have! Growth ends with a terminal molt at maturity, after which the crab never molts again. Slow growth in cold deep water makes the estimated 100 year lifespan, among the longest of any crustacean, possible. I was surprised to learn there is a small, regulated fishery in Suruga Bay (@DeadliestCatch :-)). Japan bans harvest during spawning season, and taking egg-bearing females is prohibited in most places. Females carry the eggs until hatching, talk about keeping them safe. I have watched them live at the Osaka Aquarium Kaiyukan in the Japan Deeps gallery, Monterey Bay Aquarium in Into the Deep (built around a whale-fall! They have a Spider Crab Cam 7-7 PST, too), and Loveland Living Planet Aquarium in Deep Sea gallery (PSA over :-)). Anywhere else have them? #FossilCrates

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Meet Trix! At Naturalis in Leiden, Netherlands is the awesome Trix the #Tyrannosaurus. Some estimates place it at 80% complete by bone volume (I’d love to see the denominator, and by bone count, which is my preferred score :-)). “She” (so decreed because of robustness, on the assumption females were more robust than males) is among the more complete T. rex skeletons excavated. I have heard LAGs suggest a death after 30 years old, quite ancient for a big carnivore estimated over 37’ long. Trix was named after Beatrix, a recent Dutch Queen, and lived in present-day Montana ~67 Ma. I believe it comes from the same ranch as the Dueling Dinosaurs. Big theropods are known for pathologies, and Trix does not disappoint! An infected bite wound in the right upper jaw and scratches on the left might indicate “face biting.” And broken ribs and damaged tail verts further tell the story of the hard lives these giants endured. Trix arrived in the Netherlands August 23, 2016 and 8 days later Philips spectral CT imaged four tail vertebrae as pyrite blurred standard scans. Twas unveiled to the public at her Dinosaur Hall home September 10, 2016, with that fearsome low pose, jaws at eye level, peering at visitors. Trix went on tour before hanging out in her current home: Salzburg, Barcelona, Paris, Lisbon, and Glasgow, where over 1.1 million folks observed up close this neat rex. Apparently a cast was made that can be seen in Nagasaki, Japan. I am optimistic a paper or two will drop in the next year, ideally replete with CT data, as studying mounted original bone is nigh impossible, one finds it difficult to know where real bone ends and restoration begins, which leads to frustrating guesswork. The Naturalis museum was quite artistic in its displays of dinosaurs and taxidermied wildlife. Bring a low-light lens if you are serious about photography as it can be dark in some places. Their use of technology in exhibits is at the top of the tech game, right now it holds my number one slot for the best use of mixing projectors and fossils (Burgess Shale of all things :-)). #FossilCrates

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Mia Egg in ~life position I never thought about where and how such a giant egg sat in the body until this exhibit. Yes, I’ve seen X-rays of kiwi with their massive eggs inside them, seemingly displacing organs, but not these larger beasts. Until visiting the cool Art Zoo Museum in Amsterdam, Netherlands. I saw a number of quite old moa exhibits in Italy with species I wasn’t familiar with. In the Copper Age of taxonomy, seemingly every fragment got its own species. Digging around the modern lit I was delighted to see DNA analyses and cool results! The heaviest birds were all female, the smaller ones all male, this one species per island with extreme sexual dimorphism. DNA revealed the thin-shelled eggs of Dinornis, 1 to 1.4 mm thick, despite being ~80x the size of a chicken egg! Neat strength calculations indicates they were more breakable than any of 3,434 bird species in a study. Yikes! DNA on the outer shell suggests the lighter males incubated eggs, yet even then breakage was probably common, despite being laid in sand or pumice. It seems only 36 whole moa eggs are known and I have unwittingly observed a bunch of them without appreciating their rarity. Time for a spreadsheet! Polynesians settled New Zealand in the late 13th century, and in under 150 years they wiped out the moas through hunting and habitat removal. The total human population is estimated at 2,500 at most, and moa in the eastern South Island lowlands were gone by the end of the 14th century, only 70 to 80 years after the first evidence of moa being eaten. Moa are the only late Quaternary megafauna whose extinction was clearly caused by humans. I have observed more moa skeletons in Europe than I did in a grand tour of New Zealand. Colossal is looking at resurrecting them. This should be interesting as their closest living relative is the tinamous! They share syrnix, hyoid, and larynx characters, plus a ton of DNA. Moas lost all of their forelimb bones, the tinamou have them. It would be cool to dig into that region. #FossilCrates