Oh, Hi, Bohaiornithids!

It's not often that we are introduced to a large new clade of stem-birds*, but a new paper by Wang et al. finds support for just such a thing among the enantiornithes. Named Bohaiornithidae, the family unites a few previously-known similar-looking opposite birds with two brand new species.

Phylogeny of Bohaiornithidae, modified after Wang et al. 2014.

Tyrannosaur Tooth Count

Making the rounds right now in the media is a story about a newly described, well-preserved baby Tarbosaurus bataar that helps shed some light on the way tyrannosaurs grow, as well as touches on lingering controversies. Plenty of other blogs have already covered this, so here's a link to the backstory from Brian Switek at Dinosaur Tracking.

Interestingly, the baby Tarb has 15 teeth in the lower jaw, the same number as adult T. bataar. There has been controversy over whether or not tyrannosaurs reduced their number of teeth as they grew, particularly when it comes to the controversial taxon Nanotyrannus lancensis. Nano is known from two specimens (one is nicknamed "Jane") that, depending who you talk to, might really be simply juvenile specimens of the contemporary Tyrannosaurus rex. The differences cited to separate the two boil down to differences in the braincase (certain braincase changes were demonstrated in the new juvenile Tarbosaurus as well), and the number of teeth. Adult T. rex are usually said to have only about 12 teeth in the dentary, while specimens of N. lancensis have a whopping 17. The new juvenile Tarb suggests that in at least some tyrannosaurs, the tooth count is not drastically reduced during growth from juvenile to adult. However, as the authors caution, this same pattern may not necessarily hold true for other tyrannosaurs, even very close relatives.

And, the same pattern does not hold true for the very closely related T. rex. Also making the blog rounds these last few days has been this video of Jack Horner's talk at TEDx in Vancouver (thanks to David Orr at Love in the Time of Chasmosaurs for posting the video link!).



Here Horner gives the basics of his theory that dinosaurs are oversplit, not in the subjective taxonomic sense, but in the more objective biological sense that specimens that could be shown to belong to one species actually represent juveniles of other species. You've all heard the details before, but towards the end he shows a slide (reproduced above) that is pretty damning to the crowd who support the validity of N. lancensis. In fact, adult specimens of T. rex show a very wide ranging tooth count, and it even appears to correspond with relative size (and presumably growth stage. If anything, the number of teeth seen in N. lancensis specimens are only one or two teeth outside the range of variation for T. rex proper, a minor variant that can almost certainly be attributed to ontogeny, and not some cryptic species of giant tyrannosaur lurking in the Lancian faunas that has so far only been identified by two juvenile specimens, while the very common T. rex is known from no juveniles at all.

Anybody know the tooth count for the "Tinker" specimen, currently held in a private collection?

Brilliant New Anchiornis, the Bone Wars, and More

A few quick news items while I finish up a post exploring the extent and structure of beaks in theropods...

"Dinosaur Wars" on PBS's American Experience
I haven't had a chance to check out this new PBS special on the Bone Wars (darn you, unreliable internet connection!) but the whole thing can be seen here.

"Dinomorphosis" on National Geographic's Naked Science
Airing next week, this special explores current knowledge of feathered dinosaurs. You can see the trailer here (not bad, aside from the rampant bunny hands and baffling statement that all feathered dinosaurs were carnivorous), and a related article from the magazine with photo gallery.

Be sure to check out the image of an undescribed Anchiornis specimen in the photo gallery. The preservation is utterly phenomenal, and even the previously-described color pattern is visible to the naked eye.

Also exciting is a new paper on sexual dimorphism and reproduction in the pterosaur Darwinopterus. Check out the great article summarizing the findings at New Scientist, and this skimpier Discovery article highlighting an awesome new restoration of male and female specimens by Mark Witton.

Tall Tail

This may be old news for those who attended last years SVP meeting, but news of this is (to my knowledge) breaking for the first time online. Matthew Herne has finished a complete osteology of the Australian ornithischian Leaellynasaura, abstract here: http://www.vertpaleo.org/meetings/SVPProgramAbstracts09WEB.pdf.pdf

A few surprising things here. First, Leaellynasaura is traditionally called a hypsilophodontid, or at least basal ornithopod. This study finds that it's even more basal among ornithischians, even sharing some characters with thyreophorans, so it's best placed as a basal genasaurian. Next, the tail lacks the distinctive lattice of ossified, stiffening tendons found in members of many ornithischian clades. Instead, the postzygapophyses of the tail are greatly expanded relative to other members of this order, which may have helped stiffen the back half of the tail.

Most surprisingly, the tail itself is apparently ridonkulously (technical term) long. Leaellynasaurua has over 70 tail vertebrae, more than any other ornithischians save some hadrosaurs, but more astounding is the total length of the tail, which made up 75% the total body length, being three times longer than the torso, head and neck combined. Why such a long tail? One idea floated by Dann Pigdon on the DML today is that if Leaellynasaura had a covering of filamentous feather or fur-like integument (as seen in Psittacosaurus and Tianyulong), it may have been able to use its tail for warmth during cold antarctic nights, wrapping the tail around the body like an arctic fox. It may have also been useful for territorial signaling or mating displays, especially if (as in most animals with filamentous or feathery coats) it could puff the tail up to an apparently larger size by raising its hackles.

I couldn't help taking a break from my Yixian field guide series to try restoring this hypothesis, and the results are above. Can't wait to see this paper officially in print!

The White Stripes

Back in August, I posted about a study by Vinther and colleagues looking at fossil bird feathers in an attempt to not only determine color patterns in life, but the actual colors constituting those patterns. That study looked only at Cenozoic birds, but tantalizingly, Vinther and co. promised follow-ups looking at Mesozoic birds and other feathered or proto-feathered dinosaurs.

Well, somebody has beat them to it (though, interestingly, Vinther has responded with skepticism to this newest study which has beat him to the punch though appears to use similar methods, as reported by Ed Young). Specifically, Zhang and colleagues have an online-first paper out in Nature today reporting the presence of melanosomes (pigmentation-bearing cell bits) for the first time in protofeathers. The team looked at Sinosauropteryx, Sinornithosaurus and Confuciusornis, and found pigment in all of them.

This is interesting for a few reasons, not the least of which that children's books can now officially limit their audiences imaginations by saying "no, little Billy, dinosaurs weren't whatever color you can dream of, this one here for example was black with shades of red and white patches thrown in." Firstly, this whole color-patterns-in-dinos thing was (as far as I know) first officially brought up by Nick Longrich at SVP 2002. Longrich pointed out that the thing everybody noticed about Sinosauropteryx (the stripey tail) was not an artifact of preservation, as the describers suggested, but reflected color, in the same way that prehistoric insects and fish fossils can show patterns. Based on Longrich's conclusions, I did the painting of Sinosauropteryx shown above, and this has proven largely correct (I lightened the color a bit to seem lighter browning orange, but the original was pretty close if I may say so!).

Unfortunately, being a Nature publication, this announcement comes with high prestige and itty bitty page count. The authors here promise more detailed follow-ups with more specific color patterns, and presumably Vinther et al. are also still working on their studies. Vinther's objection, which I mentioned above, is that as they had pointed out, really deciphering fossil animal colors requires a thorough understanding of how different pigment structures create color in modern birds, which is barely understood. So new discoveries with modern animals could overturn some or all of this. But, for now, all good paleoartists will reconstruct Sinosauropteryx as red-brown with a striped tail, and if Longrich was right about the rest, a bit of counter-shading.

Interestingly, the Sinosaur the new study uses is an undescribed specimen. In some news reports like this one, it is stated that Sinosauropteryx had only a feather fringe along the back, implying a partly scaly body. Now, other specimens have shown evidence of feathers on at least the lateral torso, but could this new one show evidence of a more Juravenator-type scalation on the legs and tail base (as I also restored above)? We'll see...

The Near-Bird Cometh

Above: New specimen of Anchiornis and skeletal showing feather proportions, from Hu et al. 2009. Click to embiggen.

If you've been carefully combing Dave Hone's blog for the last nine months or so (and who hasn't been?), you'll know that the initial reports on headless fossil of an interestingly bird-like supposed avialan named Anchiornis were just a warning shot. Dave reported in December of last year that protobird fans could look forward to several more complete specimens that had been recovered and not yet described. Well, it looks like the first of these is pending: J. Brougham over at Wikipedia has published a few details and a full cite from the upcoming October 1 issue of Nature, which contains the description of a nearly complete specimen preserving such cool details as a complete skull, Microraptor-style hind wings and head crest, and a phylogenetic anlysis that finds Anchiornis is in fact a basal, mid-late Jurassic troodontid (!), totally stealing Scott Hartman's thunder. If this is the case, that is, if Anchiornis can actually be demonstrated as a troodont (or even just non-dromaeosaurid) with large airfoils on the hind legs, the argument that all deinonychosaurs or even all birds went through a gliding tetrapteryx stage and are secondarily flightless to some degree just got pretty darn rock solid. Greg Paul, throw yourself a party, and set a place for William Beebe.

Being a protobird fan myself, this prompted me to immediately go to the nature.com online preprint section and start clicking refresh faster than you can whip a ram at Brewfest. Needless to say I was dissapointed and will have to start hounding J. about the paper until something pops up on the DML to whet my appetite for photos so I can get started drawing this thing. More to come one I have a chance to read the paper and collect some goss!

UPDATE:
Just been informed that not only is this on Nature's front page, but the pdf appears to be free? Or is it because I'm logged in?

My Sauropod is Bigger

There is a new record holder for second-longest dinosaur, longest if you only count bones that currently exist. Skip past the long-winded intro if you want to get to the point!

New mounted skeleton of Mamenchisaurus, in Tokyo, the longest mounted dinosaur skeleton in the world. Image by Shiziuo Kambayashi from the AP.

What is it about pissing contests over the largest dinosaurs? Who cares if Spinosaurus is a few metres longer than Tyrannosaurus? Does it really matter which super long-necked, long tailed giant sauropod is slightly longer than its nearest competitor?

Of course it does!

Well not really, but it can be a fun part of armchair paleontology to keep track of these things. I created the Wikipedia article Dinosaur Size to try and help people keep tabs on this issue using peer-reviewed sources (though for a while there a few too many Internet sources were creeping in, but we've put a stop to that).

Now, everyone gets their shorts in a bunch over the biggest theropod, because even though sauropods are nearly always bigger, they're not the ones who will try to eat Jeff Goldblum. This is evidenced by the fact that one of the biggest theropods in terms of sheer mass, Therizinosaurus, is almost always ignored in these competitions because it was probably herbivorous and looked like a giant porcupine goose with a beer belly. However, despite how cool theropods may be (i.e., extremely cool), sauropods are without a doubt the group where we find the largest dinosaurs.

So which dinosaur was largest? Well, define large. Do you mean length, height, or mass? In modern animals, mass is usually what counts. The African elephant is considered the largest land animal, even though the giraffe is taller and the reticulated python is longer. The most massive, and therefore largest, dinosaur known from decent remains that still exist is a bit of a tie game right now. Traditionally, the largest sauropod known is cited as the titanosaur Argentinosaurus, with rational mass estimates ranging between 78 and 83 tonnes. However, several other titanosaurs were about the same size, if not bigger, including Puertasaurus and the horrifically named Futalognkosaurus (note that the official name even includes a misspelling, yikes!).


Scale diagram showing several of the largest dinosaurs discussed in this post. Green: Diplodocus. Orange: Supersaurus. Purple: Argentinosaurus. Blue: Sauroposeidon. Grey: Bruhathkayosaurus. Red: Amphicoelias. Scale bar = 40m. Image by Matt Martyniuk, licensed.

The new goss here though, to finally get to the reason for this post, is that the record for longest dinosaur has changed... sort of (see final paragraph, below). When I was a kid, I was enthralled by the longest known dinosaur according to several of my books, the "Seismosaurus" (earthquake lizard). This monster diplodocid (whip-tailed sauropod) was said to be over 130ft in length. Well, those initial estimates were a little too hopeful, and based on the mis-identification of a tail bone which threw the estimates off by up to 30%. More reasonable estimates place its total length at a mere 33.5m (110ft), and furthermore, it turned out to likely be just a slightly oversize specimen of Diplodocus anyway.

The downsizing of Seismo--er, Diplodocus left the length champion to its cousin, Supersaurus. As the preparation of a fairly complete skeleton nicknamed "Jimbo" by Scott Hartman showed, Supersaurus probably reached a total length of 34m, or 112ft, surpassing both Diplodocus and weight champion Argentinosaurus by a meter or two (in the process robbing the titanosaurs of their clear victory in both units of measure).

However, now a new champion emerges by a neck (I'll be here all weekend folks!). A new specimen of the mega-necked Chinese sauropod Mamenchisaurus unearthed in 2001 was initially reported as the largest of its kind at a respectable, but short, 30m (98ft). However, a surprise came when they assembled a reconstructed skeleton for a new exhibition opening in Tokyo: the specimen actually measures a whopping 35m long, or 115ft, beating out Supersaurus for the title of longest known dinosaur. See photo at top of this post.

Extraordinarily accurate (down to the scales) illustration on Mamenchisaurus by Steve OC, licensed.

That is, if you don't count Amphicoelias. This monster, known from a single partial vertebrae that was 8ft tall and would have been 12 if complete, was very similar to Diplodocus and, scaling up from the same bone in that animal, Amphi would have been at the very least 40m long (131ft) and probably in the area of 120 tons, easily trumping all other contenders in every category: length, weight, and height (read the Wiki I started and wrote most of on Amphi here). So far the only contender to that throne is the even more dubious Bruhathkayosaurus, which is known from a poorly preserved, poorly published, and basically never studied leg bone sometimes thought to be a tree trunk, and even if the size the describers said it was is probably vastly overestimated in published surveys. For now, Amphi is the king, but its smaller cousins with better remains are inching closer.

Four Wings Bad, Two Wings Good?

While helping to review a painting of Velociraptor posted to Gondolend, the artist brought up an outdated drawing of Sinornithosaurus she'd found among the top hits on Google, showing generally poor drawing skills and a likely inaccurate frond-tail of feather extending all the way to the hip (dromaeosaurs all seem to have had only a spray of vaned feathers at the tip of the tail, the rest being covered in down). This drawing is one of mine. As I've been updating my web site, I figured Sinornithosaurus should go to the top of the list for things to take a second stab at illustrating.

But how? In his book Dinosaurs of the Air, Greg Paul gave his sinornithosaurs something no fossils of them preserve--Microraptor-like wings on the back legs. It's a close relative of Microraptor, sure, but why do this with no evidence? In the travelling Feathered Dinosaurs exhibit I was lucky enough to see at the AMNH, the Liaoning diorama also contained a sinornithosaur with small, microraptorian hind wings. I checked the fossils again. Was I missing something? It seemed like a consensus was emerging with no published evidence. Sounds like some juicy behind the scenes goss was at work here.

It was. I present to you an unpublished specimen (NGMC 00-12-A, from Ji's thesis) of Sinornithosaurus (EDIT: Or is it a large, old Microraptor? See Mickey Mortimer's comments below) with what looks to be small wings on the hind legs.
Not only that, but as predicted by GSP and the AMNH model, it also appears to have full wings with primary (not just secondary as suggested by the preservation of the "Dave" specimen) wing feathers.

But... is it real? A few posters to DinoForum have admitted tentative wariness about even the hind-wing sporting Microraptor. After all, portions of the published Micro specimens are known to have been, ah, "enhanced" to make them more appealing to fossil collectors on the secondary fossil market (which is like half the Chinese economy and is only illegal in name). Sure, many specimens of Microraptor have been found with hind wings, but only two have been published on, and all came from private collectors. Specimens dug up by pros have lacked this feature, but are also more poorly preserved.

In the photo above, you can see that the feathered portion of the leg is on a separate piece of rock from the rest. Granted, specimens like this, at this size, are generally pretty fragmented, but it also gives fakers leeway to swap pieces in and out in order to make the piece more attractive. This practice isn't necessarily malicious, the enhancers just want to create a more artistic piece with no concern for science. Nor is it limited to China (remember Irritator? It got that name for a reason). Still, it's very prevalent there, to the point where many "museums" (mostly private collections that admit the public like the old Cabinets of Curiosity) contain mostly faked fossils. Professional museums in China, like the IVPP, are mainly clean from what I've heard. The pros are aware of this problem and I'd like to think most specimens that hit press are properly vetted, especially in the aftermath of Archaeoraptor. But when it comes to unpublished specimens, all bets are off, so be careful out there, paleoartists!

Long story short, I'll be re-illustrating Sinornithosaurus, but the hind wings will go in a separate layer, just in case...

[Top image: Very old, outdated Sinornithosaurus drawing by yours truly. All rights reserved.]
[second image from top: Sinornithosaurus by FunkMonk, lisenced.]

The Story of Lori

The origin of birds has always been a dicey subject. If you define "bird" as the clade including Archaeopteryx and modern species, as most paleonotolgists currently do, then the Late Jurassic Archaeopteryx ("Archie"--all the really cool and/or important fossils need a good nickname!) has always been the first bird, and because of the definition, probably always will be unless some of it's very close cousins are ever unearthed. The problem is that the closest supposed relatives of birds, the deinonychosaurs ("raptors" and relatives) should naturally pre-date Archie, if they're generally ancestral to it. Unfortunately, fossils from this group come almost exclusively from the Cretaceous period, well after Archie went extinct. The dwindling bird-are-not-dinosaurs crowd (BANDits) has historically seized on this as an attempted "gotcha" to rational human beings. After all, if birds evolved from dinosaurs, how come all the bird-like dinosaurs lived after the first birds?

It's true that the fossil record of pre-Archie maniraptorans is pretty slim, but paleontologists infer they must exist based on ghost lineages (see previous post on this topic). In that previous post, I mentioned the case of "Lori", the pre-publication nickname Scott Hartman has given to his (wait for it) Late Jurassic troodontid! Found in the Morrison Formation (not exactly known for its small dinosaur preservation, its more of an 8-foot vertebrae kinda spot), Lori would have lived at roughly the same time as Archaeopteryx, not early enough to be ancestral, but still enough to shoot down the old ghost lineage problem pretty thoroughly.

Scott (pic at right) first started discussing this find in more private venues like Gondolend, but it's safe to say the goss has spread far and wide in the years since then. He's provided some of us with an exclusive sneak peak at his own skeletals (he's pretty much a skeletal illustration guru, check out his awesome Web site), but the years have gone by and Lori has still not seen print nor a proper name.

Well, inside sources have sent the goss stunning evidence that a name has indeed been chosen, and possibly, that an official publication is getting close (it appears to be a cladogram for the paper, with the old Lori skeletal clearly labelled with its shiny new genus name). Far be it from me to leak the name pre-pub and risk creating sticky nomen nudum situations (I'm sure Scott doesn't envy Jim Jensen), but rest assured it preserves a traditional troodontid naming convention, as well as bearing some similarity to a recent dromaeosaurid name.

I wanted to post some of the great reconstructions of Lori that have already been produced and shared by members of the private boards where it's a well-known subject, but I can't seem to find any online. Scott is a pretty active member of these communities so it's only natural people are showing his find a little more discretion than would be normal for exciting, unpublished dinosaurs. I feel the same way, so the censored clipping of my source is all you're getting out of me. I'm sure a 3-year backlog of killer illustrations will appear out of the woodwork once it's officially published (didn't we even do a Lori draw-off at some point?) so as Tom Holtz would say, W4TP...

(pic above right: Jim Jensen with his Ultrasauros. He probably would have preferred to use a 'u' at the end there instead of an 'o', but the goss got a little out of hand).

"They look like big, good, strong hands, don't they?"

Just popping in to report on the ongoing saga of the new Deinocheirus specimen(s?).

For those who haven't been keeping up, rumors of one or more new finds from this age-old dino mystery have been swirling for a few months now. While a new find was whispered of over a year ago, the real action didn't start until Michael Ryan posted on his blog regarding Phil Currie's re-discovery of the original quarry where the infamous "terrible hands" and their adjoining titanic arms were first found in the late 1960s. He ended the short post with the tantalizing statement that they'd found more of the skeleton.

[Reconstruction of Deinocheirus as an ornithomimid by Wikipedia illustrator and DinoForum member known as FunkMonk, some rights reserved. More on this image below]

As a child of the '80s, and thanks to any number of old dinosaur books for kids, Deinocheirus stands out at THE mystery dinosaur. Gigantic, clawed arms of a predatory dinosaur larger than anything else like them by an order of magnitude. What kind of creature could these possibly have belonged to? The imagination runs wild.

Thanks to phylogenetic studies done in the 1990s and 2000s, most paleontologists have concluded that it was probably a gigantic ornithomid, or "ostrich dinosaur," though just what a 40ft ornithomimid would look like and what kind of specialised adaptations it must have had remain a mystery.

Well, a mystery to most. I brought up Ryan's blog post at DinoForum last November to fish for clues. And boy did I get them. Several people posted tortured cries of "wait for the paper." I can't imagine the Machiavellian pleasure people must take in knowing the answer to such a compelling and long-standing mystery and not being able to talk about it. They must feel like the creators of Lost.

Most people couldn't resist posting more clues, or teaser answers to questions in that thread. T. Mike Keesey of Dinosauricon fame knows what it is. Is it a giant ornithomid, or something more? Says Keesey: "Oh, it's more." Keesey also dropped the bomb that the find in the original quarry was NOT the one he was thinking of. More than one Deinocheirus? A new member of the deinocheirid family? Something else? Somebody knows what it is. Somebody knows. Ok, now I'm just sounding like the creepy ginger guy from Watchmen. Anyway, more rumors from those in the know suggested that, while Currie and Ryan's site had turned up new remains, they weren't much. The other new find, however, seemed to be something much more complete.

By the end of January, Scott Hartman weighed in... by laughing at us poor blind plebs. Openly mocking our futile attempts at solving the puzzle. Yup, creators of Lost all right.

But, today, another solid clue, perhaps the most solid yet. Not a clue: an answer.

FunkMonk (mentioned above, sorry, don't know your real name dude) had posted a thread for critiques of his artwork a while back, also at DinoForum. Now the subject of his Deinocheirus has come up again. Scott Hartman reckoned a giant ornithomimid should be more graviportal (with heavy and stout limbs, unlike the lithe form of small, fast ornithomimds). But, it was an old thread, and the picture was done before rumors of the new find(s), and Keesey's implication that it might not be an ornithomimid. Funk didn't want to put more effort into a drawing that might be completely off base. Well, someone came along and put that one to rest.

"It's an ornithomimid."

Stay tuned, gosshounds, as the saga continues to unfold!

[Photo: cast of the currently-known Deinocheirus specimen from Wikipedia, some rights reserved.]

Save the Squatter!

Everybody and your mom (their mother?) is blogging about "The Squatter" finally getting published. This is the amazing trace fossil in St. George, Utah that shows not only the footprints of a dilophosaur-sized theropod, but a nearly complete lower-body impression. This is not where the dinosaur walked, but where it sat down to take a breather from constantly chasing things and roaring its fool head off (if every CGI dinosaur show on Discovery is to be believed). (They're not).

The impression includes the pubic boot it sat on, feet/metatarsals, tail, and--most importantly--hands. The hands prints were left side-on, offering the final piece of conclusive proof that theropods did not "pronate" the hands. They could not point palm down like dribbling a basketball, but like a bird wing, were locked with palms facing each other, like holding a basketball. This is something paleontology types have known for a long time based on anatomical studies but it's nice to have behavioral proof. Also nice to have it confirmed in such a primitive species, since many of said anatomical studies were based on more advanced, more bird-like species. Years ago when rumors of this find first hit the tubes, it was said to preserve feathers as well, but that's probably just a bunch of plant material it was sitting on. It's unlikely such a primitive dinosaur would have had feathers (they appear to be restricted to advanced coelurosaurs and birds).

So why does this fossil need saving? Well, it already narrowly avoided being intentionally destroyed in order to build the rear wall of the St. George Dinosaur Discovery Site Museum (ironic, eh?). Now the museum has built a section around the fossil in order to help preserve it from erosion, but it's still weathering ever so slowly, and the museum is too underfunded to really go to the lengths they need to preserve it over the long-term.

That's where we come in. This whole story was brought to by Sarah Spears, former employee of the museum, has put out a call for donations at her blog Gombessa Girl (which also has a more in-depth discussion of the specimen and its predicament).

So, dino fans, you can help save the Squatter by visiting http://www.dinosite.org and becoming a member, joining their Adopt-A-Track program, or buying some swag from the gift shop (which has some pretty cool casts of the dino tracks for sale).

Oh, and for you research-hungry gosshounds, the paper describing the Squatter is online for absolutely free at PLoS ONE, including CC licensed images like the awesome reconstruction here, by awesome wildlife artist Kyoht Luterman.

New bird and some crazy, spikey beaks

As many of you will know, up until the advent of modern birds (Aves), most flying dinosaurs had teeth. Real teeth, as in little things covered in enamel and set into sockets in the jaw. Alas, however, all the toothed birds went extinct at the end of the Mesozoic, leaving only the boring old toothless birds to survive to the present day.

But some Cenozoic birds still were able to occupy niches left by toothed Mesozoic seabirds, and by a quirk of evolution developed "pseudoteeth" to suit this task. This group, the pelagornithids, were also among the largest flying birds that ever lived. Relatives of pelicans and boobies, these superficially albatross-like birds could grow up to 6 m in wingspan (that's 20ft for the seppos). And they were pretty recent, with the last species dying out only three million years ago or so.

The "teeth" of pelagornithids were actually sharp, saw-like serrations of the beak. This week, National Geographic announced the discovery of the most complete pelagornithid skull known. It's crazy cool looking, as you can see by the photo in the link. This specimen is from about the middle of the pseudo-toothed bird era, and lived about ten million years ago (the earliest records are from 58 million years ago, showing that these birds started filling in for their toothed forebears shortly after the big extinction). The article doesn't mention if this represents a new species, so stay tuned for more pseudo-toothed goss.

Image from Wikipedia of Osteodontorins by NTamura, licensed under Creative Commons Attribution 3.0 Unported.