Big dinos! Spinosaurus and Dreadnaughtus.

When I first saw an image of Spinosaurus aegyptiacus sometime way back when I was a kid crazy about dinosaurs--the image had no caption indicating the species--I thought it was someone's silly conflation of a Jurassic or Cretaceous theropod with a Permian era sail-backed synapsid like Dimetrodon.  I later learned that it was a real dinosaur, that its fossils had been found in Egypt, but that the only known fossil remains had been destroyed in a bombing raid on Munich during World War II.

Thanks to a nomad in Morocco, who found fossil bones that came to the attention of paleontologist Nizar Ibrahim, a post-doc at the University of Chicago, paleontologists there were able to create a reconstruction of Spinosaurus that strongly indicates that, like a present day crocodile (or duck), it had a semi-aquatic life. It was larger than any other known carnivorous dinosaur, including Giganotosaurus. Indeed, it was likely piscivorous, dining on the large fish that swam in the shallow waters of the coastal region that was North Africa in the Cretaceous.

My last post on dinos was about the smallest dinosaur yet discovered, Ashdown maniraptora. Now there's a new biggest, discovered in Argentina, which now vies with China as the richest source of new dinosaur discoveries. It is, of course, a sauropod, one of those immense, long-necked, long-tailed, big-bodied herbivores we boomers knew in our childhood as Brontosaurus, but later learned was properly named Apatosaurus (the story of how this happened is here).

  This was sad news for the Piltdown Men, who took their name from what may have been the greatest paleontological hoax ever.

As we boomers grew older, we learned of other sauropods, like long, slender Diplodocus and Brachiosaurus, with its towering neck. In recent years a large number of new sauropod species have been found in places like Brazil and Utah. Now, the biggest yet has been found in Argentina, weighing 65 tons, more than twice the weight of Brachiosaurus; indeed, more than an empty Boeing 737. It's been given what I think is a very appropriate name: Dreadnaughtus.

I haven't included an image of Dreadnaughtus because Anne Elk (see clip above) has explained what all sauropods look like. If you still need help, there's a picture of one on the wall behind.

Addendum: I neglected to credit the Spinosaurus image to "Barry's Dinosaur Info" in Dinotopia. "Barry's", in turn, credits the image to Arthur Weasley. Perhaps the same vein, I learned through "Barry's" of a dinosaur called Dracorex hogwartsia.

Oldest fossils?

David Wacey/New York Times

This seems to be a year for superlatives in paleontology--well, maybe, if you consider smallest dinosaur to be a superlative. Anyway, Nicholas Wade reports in yesterday's New York Times that "[a] team of Australian and British geologists have discovered fossilized, single-cell organisms that are 3.4 billion years old and that the scientists say are the oldest known fossils on earth." If these are indeed fossils of living organisms, they show that life evolved very early in the earth's history, at a time when, as Wade notes, the atmosphere was rich in methane, and only a few islands rose above the surface of an ocean that was the temperature of a hot bath. The Australian sandstone formation in which these structures (see photo above by David Wacey of the University of Western Australia who, along with Martin D. Brasier of the University of Oxford, discovered them) were found was, 3.4 billion years ago, a beach on one of those islands.

The Littlest Dinosaur: Ashdown Maniraptoran

Matt Martyniuk/University of Portsmouth

Being the smallest dinosaur is like being the biggest Chihuahua: it goes against the point of the thing. Of course, "smallest dinosaur" is always a qualified designation; "of which we know" is the unstated qualifier. The present holder of the title is the "Ashdown Maniraptoran," from the early Cretaceous of southern England, thought to have been about thirteen to sixteen inches in length and, according to the restoration shown above, to have looked something like a partridge in search of a pear tree. This restoration is based on one fossil cervical vertebra found by amateur fossil hunter Dave Brockhurst, who kept it in a drawer for about two years before sending it to University of Portsmouth paleontologists Darren Naish and Steve Sweetman, who identified it as coming from a very small adult dinosaur of the clade Maniraptora (also the title of a friend's excellent website).

You may quite reasonably wonder how this restoration could be made based on a single vertebra. Matt Martyniuk, the artist who made it, owns that it is "entirely speculative" but explains his methodology in this post and defends it in the discussion thread following.

An important fossil discovery: Liaoconodon hui, a Mesozoic mammal with a transitional middle ear.

In the clip above, Jin Meng, curator of fossil mammals at the American Museum of Natural History, describes how the well-preserved fossil of Liaoconodon hui, a mammal that lived in the Mesozoic era -- the age of dinosaurs -- shows the development of middle ear structure that characterizes later mammals, including ourselves.

News of the very old and the old: dinosaurs and wine

PBS Newshour

This has been a productive time for paleontologists. From Argentina, a dinosaur hot spot in recent years, comes news of what may be one of the most primitive of theropods, Eodromaeus ("dawn runner") murphi (see illustration at left). This scrawny four-foot-long critter lived in the Triassic Period, about 230 million years ago, when dinosaurs were just beginning to emerge, and before they attained the dominance they would enjoy in the succeeding Jurassic and Cretaceous Periods. Eodromaeus is early in a family tree that would later branch to include such diverse progeny as T. Rex and Tweety Bird. Read more about it in this PBS Newshour story.

Utah, long a preeminent source of dinosaur fossils, produced eight new species (see this Deseret News article) in 2010. One of these, Seitaad ruessi, named for a Navajo legendary sand demon because its fossils were found in petrified sand, is a small, early member of the sauropod group, the familiar long-necked herbivores that evolved into giants like Apatosaurus. Another, Abydosaurus mcintoshi, is a later, larger sauropod. Two are iguanadonts, bipedal herbivores that are relatives of Iguanadon, the second dinosaur ever to be described and named. One, Hippodraco ("horse dragon") scutodens, is relatively small for this group, while the other. Iguanacolossus fortis, as its name proclaims, is massive (See their comparative sizes, and read more about them, in this Open Source Paleontologist article). Three, Diabloceratops eatoni, Utahceratops gettyi, and Kosmoceratops richardsoni, are ceratopsians; horned dinosaurs similar to Triceratops. Only one is a carnivorous theropod: Geminiraptor suarezarum. This dinosaur got its name, which means "twin predatory thief of the Suarezes", in honor of the twin sisters Marina and Selina Suarez, both graduate students at Temple University, who studied the geology of the area where the fossils were found (see this Environment News Service article). Geminiraptor is an early troodontid, a group of small, agile predators related to Velociraptor.

Now, from paleontology to archaeology and anthropology, and to one of my favorite topics: wine. I've posted before about the role of alcoholic beverages in the development of civilizations. This Washington Post article reports the discovery of the remains of "a surprisingly advanced winemaking operation" that dates to about 6,000 years ago, located in a cave near an Armenian village. As Slate notes: "It gives 'mis en bouteille dans nos caves' a literal flavor".

A missing link found.

This one, Cerasinops hodgskissi, is between American and Asian dinosaurs.

Was T. Rex a basso profundo?

Get the low-down here.

Palms in the Catskills?

No, this isn't a global warming alarm. It seems that there were palm-like trees growing in that region in the Middle Devonian, some 380 million years ago (see here).

Update: Geology maven Twiffer points out that, in the Middle Devonian, the bit of tectonic plate on which the Catskills now sit was at a latitude comparable to the present-day Caribbean, so the presence of palms, or something possibly ancestral to them, is not surprising.

Although I'm confident that Twiffer is right about this, statements about ancient geological dispositions bring to mind a quotation from Mark Twain's Life on the Mississippi, which he presented as a critique of scientific speculation, but is actually an attack on simple-minded extrapolation:

In the space of one hundred and seventy-six years the Lower Mississippi has shortened itself two hundred and forty-two miles. That is an average of a trifle over one mile and a third per year. Therefore, any calm person, who is not blind or idiotic, can see that in the Old Oolitic Silurian Period, just a million years ago next November, the Lower Mississippi River was upwards of one million three hundred thousand miles long, and stuck out over the Gulf of Mexico like a fishing-rod.

Right! The lizard-fish conversion. Very easy.

We have good clues about how fish evolved into land-dwelling animals, but how about those great aquatic reptiles of the Mesozoic, the ichthyosaurs, mososaurs and plesiosaurs? How did they evolve from landlubbers to seafarers?

When I saw a story a few days ago of a fossil primitive crocodilian, of the species Thalattosuchia, found in Oregon, I noted how much the artist's rendering looked like an ichthyosaur, despite the lack of a dorsal fin. This made me wonder: Did the ichthyosaurs evolve from primitive crocodilians? Evidently not, since the earliest thalattosuchian fossils found so far are from the Jurassic, while ichthyosaurs appeared as early as the Triassic, though they are believed to have evolved from more primitive diapsids that may also have been ancestral to crocodilians. That raised another question: Could crocodilians have evolved from ichthyosaurs, thus providing an example of evolution taking one group of creatures from land to sea, then back to a semi-terrestrial existence? Again, the answer seems to be no, as fossil crocodilians (but not thalattosuchians) have also been found in Triassic strata.

So, the superficial resemblance between thalattosuchians and ichthyosaurs (long beaks; vertical, fish-like tails) may be an example of convergent evolution.

Update: On the subject of Triassic crocs, Brooklyn Heights Blog colleague (if a newbie to the team may be so bold) qfwfq kindly gives me a link to a piece about an early croc, Effigia okeeffeae, "discovered" in a collection of unclassified fossils at the American Museum of Natural History. This critter ran on two legs and bore a strong resemblance to ornithomimid dinosaurs that didn't appear until the late Jurassic, about eighty million years after Effigia. Ornithomimids are themselves cited as examples of convergent evolution with ratite birds (for example, ostriches), so adding Effigia to the mix gives us an example of triple convergence.

More Florida weirdness.

Whenever I go there, I get the feeling I'm going back to the Mesozoic, where an encounter with Allosaurus fragilis in the thin forest scrub (as here, in the Naples Botanical Garden) isn't unthinkable (photo courtesy of news-press.com, via dinosaurnews).

Update: For a cautionary (pre-dino replicas) tale about the Naples Botanical Garden, see this.

New dino species found in Brazil.

South America seems to be the hot spot these days for dinosaur discoveries. At 39 feet and nine tons, Maxakalisaurus topai isn't particularly big as sauropods go, but this Reuters article points out, it's a significant discovery because it appears to provide an evolutionary link to a branch of the Titanosauridae found in more recent Cretaceous formations in Argentina.

Kids may love or hate it based on its name. I'm not sure how the Maxakali, the tribe from which the name is derived, pronounce the "X"; i.e., is it "Macks-a-kal-i" or "Mash-a-kal-i"?

I'm very impressed by the reconstruction of the head of the theropod Mapusaurus roseae, which you can find by scrolling down a bit in the linked article.