Help me find this notebook

January 30, 2017


TL;DR: if you know where I can get a notebook just like this one, or from the same manufacturer and made to the same specs, or have one of your own that I could buy off you (provided it’s mostly unused), please let me know in the comments.


Long version:

This is the best notebook I’ve ever used. The cover is 7.25 x 10 inches, made of some kind of dense and probably recycled paper board. It’s twin-loop wire bound, has a button-and-string closure and a separate loop of board inside the back cover to hold a pen or pencil. Heavyweight cream paper. Has a fossil fish, Eoholocentrum macrocephalum, embossed on the cover, with the Linnean binomial properly capitalized and italicized.

I’ve used loads of other notebooks, including several sizes and designs of Moleskine and Rite-in-the-Rain, and this one is by far my favorite. Why? It lies flat when open or folded back on itself, the wire binding has never hung up, torn a page, or otherwise malfunctioned in over four years of travel and heavy use, and the pen holder and button string closure are perfect for my purposes. I’ve never had a notebook with an elastic band that didn’t wear out, and I usually have to build my own pen loops out of tape.

The one I have was a gift from Mark Hallett, who picked it up at SVP some years ago. Neither of us know who made it. But I’d really like to have another one, because mine is almost full. So far all of my searching online and off has failed to turn up a notebook like this, either another original or one with the same features made to the same specs. So if you know something about this, please pass it on!

Several drinks later, they all die and somehow become skeletonised, and that’s how they all land up on a table in my office:

2016-04-14 11.12.52

Top left: pieces of monitor lizard Varanus exanthematicus. Cervical vertebrae 1-7 on the piece of paper, femora visible above them, bits of feet below them. Awaiting reassembly. The whole skeleton is there.

Top right, on a plate on top of some lizard bits: skull, cervicals and feet of common pheasant Phasianus colchicus. The skull has come apart, and I can’t figure out how to reattach the quadrates. One of the feet is cleanly prepped out and waiting to be reassembled, while the other retains some skin for now.

Bottom left: skull and anterior cervicals of red fox Vulpes vulpes. Lots of teeth came out during the defleshing process, and will need to be carefully relocated and glued after the skull has finished drying out.

Bottom right: skull and anterior cervicals of European badger Meles meles. The skull is flat-out awesome, and by far my favourite among my mammal skulls. If tyrannosaurs were medium-sized fossorial mammals, they’d have badgers’ skulls for sure. A few teeth that came out have been glued into place; once the glue is dry, this skull is done.


The pheasant comes apart

March 26, 2016

A couple of weeks ago, I was given a pheasant, which I reduced to science and food. When we last saw it, it was down to a skinned and partially defleshed head/neck and feet. It’s been through a couple of defleshing rounds since then, and today I was able to take it fully apart:

2016-03-26 12.31.09

At the moment, the bits are laid out on this plate, drying. Small amounts of soft-tissue remain (and more on the second foot), which may need the attentions of invertebrates to fully clean.

It pains me to admit, but even though I have kept the cervical vertebrae, for most people the skull will be the interesting part. Here it is in a little more detail, disarticulated into about ten units. The mandible is to the right of this image; the rostrum to the left of it, and the main cranial section to the left again:

2016-03-26 12.31.47

To the sides are the bones that laterally connect the rostrum to the braincase: zygomatics, quadrates and what have you. They are laid out roughly in the right positions, though the two quadrates may have been switched. Once everything is clean and dry, I’ll glue it back together, using my ostrich skull to help guide me.

The feet are trickier. Here’s the one I took apart:


2016-03-26 12.31.35

At the top of the photo, you see a mass of ossified tendons, which operated the toes from more proximal areas. This is how all bird feet work, and it’s such a great scheme that it seems weird everything doesn’t do it.

Below these, we have the tarsometatarsus to the right, and the four digits to the left. Each digit has its phalanges in the right order, but I don’t know what order the digits themselves should be in. To help me get that right, I pulled out of prepping the other foot down, hence its current semi-zombified state:

2016-03-26 12.31.23

I’m hoping it’s still intact enough to guide me as a reassemble the bones of the other foot. (Once that’s done, I may also take this one to completion, or I may decide that one pheasant foot is enough.)

Anyway, it’s nice to be progressing this specimen. Next, I need to figure out the best way to decapitate a medium-sized mammal (like a fox or badger) without damaging the skull, and using no special equipment.

Notocolossus is a beast

January 20, 2016

Notocolossus skeletal recon - Gonzalez Riga et al 2016 fig 1

(a) Type locality of Notocolossus (indicated by star) in southern-most Mendoza Province, Argentina. (b) Reconstructed skeleton and body silhouette in right lateral view, with preserved elements of the holotype (UNCUYO-LD 301) in light green and those of the referred specimen (UNCUYO-LD 302) in orange. Scale bar, 1 m. (González Riga et al. 2016: figure 1)

This will be all too short, but I can’t let the publication of a new giant sauropod pass unremarked. Yesterday Bernardo González Riga and colleagues published a nice, detailed paper describing Notocolossus gonzalezparejasi, “Dr. Jorge González Parejas’s southern giant”, a new titanosaur from the Late Cretaceous of Mendoza Province, Argentina (González Riga et al. 2016). The paper is open access and freely available to the world.

As you can see from the skeletal recon, there’s not a ton of material known from Notocolossus, but among giant sauropods it’s actually not bad, being better represented than Argentinosaurus, Puertasaurus, Argyrosaurus, and Paralititan. In particular, one hindfoot is complete and articulated, and a good chunk of the paper and supplementary info are devoted to describing how weird it is.

But let’s not kid ourselves – you’re not here for feet, unless it’s to ask how many feet long this monster was. So how big was Notocolossus, really?

Well, it wasn’t the world’s largest sauropod. And to their credit, no-one on the team that described it has made any such superlative claims for the animal. Instead they describe it as, “one of the largest terrestrial vertebrates ever discovered”, and that’s perfectly accurate.

Notocolossus limb bones - Gonzalez Riga et al 2016 fig 4

(a) Right humerus of the holotype (UNCUYO-LD 301) in anterior view. Proximal end of the left pubis of the holotype (UNCUYO-LD 301) in lateral (b) and proximal (c) views. Right tarsus and pes of the referred specimen (UNCUYO-LD 302) in (d) proximal (articulated, metatarsus only, dorsal [=anterior] to top), (e) dorsomedial (articulated), and (f) dorsal (disarticulated) views. Abbreviations: I–V, metatarsal/digit number; 1–2, phalanx number; ast, astragalus; cbf, coracobrachialis fossa; dpc, deltopectoral crest; hh, humeral head; ilped, iliac peduncle; of, obturator foramen; plp, proximolateral process; pmp, proximomedial process; rac, radial condyle; ulc, ulnar condyle. Scale bars, 20 cm (a–c), 10 cm (d–f). (Gonzalez Riga et al 2016: figure 4)

Any discussions of the size of Notocolossus will be driven by one of two elements: the humerus and the anterior dorsal vertebra. The humerus is 176 cm long, which is shorter than those of Giraffatitan (213 cm), Brachiosaurus (204 cm), and Turiasaurus (179 cm), but longer than those of Paralititan (169 cm), Dreadnoughtus (160 cm), and Futalognkosaurus (156 cm). Of course we don’t have a humerus for Argentinosaurus or Puertasaurus, but based on the 250-cm femur of Argentinosaurus, the humerus was probably somewhere around 200 cm. Hold that thought.

Notocolossus and Puertasaurus dorsals compared

Top row: my attempt at a symmetrical Notocolossus dorsal, made by mirroring the left half of the fossil from the next row down. Second row: photos of the Notocolossus dorsal with missing bits outlined, from Gonzalez Riga et al (2016: fig. 2). Scale bar is 20 cm (in original). Third row: the only known dorsal vertebra of Puertasaurus, scaled to about the same size as the Notocolossus vertebra, from Novas et al. (2005: fig. 2).

The anterior dorsal tells a similar story, and this is where I have to give González Riga et al. some props for publishing such detailed sets of measurements in the their supplementary information. They Measured Their Damned Dinosaur. The dorsal has a preserved height of 75 cm – it’s missing the tip of the neural spine and would have been a few cm taller in life – and by measuring the one complete transverse process and doubling it, the authors estimate that when complete it would have been 150 cm wide. That is 59 inches, almost 5 feet. The only wider vertebra I know of is the anterior dorsal of Puertasaurus, at a staggering 168 cm wide (Novas et al. 2005). The Puertasaurus dorsal is also quite a bit taller dorsoventrally, at 106 cm, and it has a considerably larger centrum: 43 x 60 cm, compared to 34 x 43.5 cm for Notocolossus (anterior centrum diameters, height x width).

Centrum size is an interesting parameter. Because centra are so rarely circular, arguably the best way to compare across taxa would be to measure the max area (or, since centrum ends are also rarely flat, the max cross-sectional area). It’s late and this post is already too long, so I’m not going to do that now. But I have been keeping an informal list of the largest centrum diameters among sauropods – and, therefore, among all Terran life – and here they are (please let me know if I missed anyone):

  • 60 cm – Argentinosaurus dorsal, MCF-PVPH-1, Bonaparte and Coria (1993)
  • 60 cm – Puertasaurus dorsal, MPM 10002, Novas et al. (2005)
  • 51 cm – Ruyangosaurus cervical and dorsal, 41HIII-0002, Lu et al. (2009)
  • 50 cm – Alamosaurus cervical, SMP VP−1850, Fowler and Sullivan (2011)
  • 49 cm – Apatosaurus ?caudal, OMNH 1331 (pers. obs.)
  • 49 cm – Supersaurus dorsal, BYU uncatalogued (pers. obs.)
  • 46 cm – Dreadnoughtus dorsal, MPM-PV 1156, Lacovara et al. (2014: Supplmentary Table 1) – thanks to Shahen for catching this one in the comments!
  • 45.6 cm – Giraffatitan presacral, Fund no 8, Janensch (1950: p. 39)
  • 45 cm – Futalognkosaurus sacral, MUCPv-323, Calvo et al. (2007)
  • 43.5 cm – Notocolossus dorsal, UNCUYO-LD 301, González Riga et al. (2016)

(Fine print: I’m only logging each taxon once, by its largest vertebra, and I’m not counting the dorsoventrally squashed Giraffatitan cervicals which get up to 47 cm wide, and the “uncatalogued” Supersaurus dorsal is one I saw back in 2005 – it almost certainly has been catalogued in the interim.) Two things impress me about this list: first, it’s not all ‘exotic’ weirdos – look at the giant Oklahoma Apatosaurus hanging out halfway down the list. Second, Argentinosaurus and Puertasaurus pretty much destroy everyone else by a wide margin. Notocolossus doesn’t seem so impressive in this list, but it’s worth remembering that the “max” centrum diameter here is from one vertebra, which was likely not the largest in the series – then again, the same is true for Puertasaurus, Alamosaurus, and many others.

Notocolossus phylogeny - Gonzalez Riga et al 2016 fig 5

(a) Time-calibrated hypothesis of phylogenetic relationships of Notocolossus with relevant clades labelled. Depicted topology is that of the single most parsimonious tree of 720 steps in length (Consistency Index = 0.52; Retention Index = 0.65). Stratigraphic ranges (indicated by coloured bars) for most taxa follow Lacovara et al.4: fig. 3 and references therein. Additional age sources are as follows: Apatosaurus[55], Cedarosaurus[58], Diamantinasaurus[59], Diplodocus[35], Europasaurus[35], Ligabuesaurus[35], Neuquensaurus[60], Omeisaurus[55], Saltasaurus[60], Shunosaurus[55], Trigonosaurus[35], Venenosaurus[58], Wintonotitan[59]. Stratigraphic ranges are colour-coded to also indicate geographic provenance of each taxon: Africa (excluding Madagascar), light blue; Asia (excluding India), red; Australia, purple; Europe, light green; India, dark green; Madagascar, dark blue; North America, yellow; South America, orange. (b–h) Drawings of articulated or closely associated sauropod right pedes in dorsal (=anterior) view, with respective pedal phalangeal formulae and total number of phalanges per pes provided (the latter in parentheses). (b) Shunosaurus (ZDM T5402, reversed and redrawn from Zhang[45]); (c) Apatosaurus (CM 89); (d) Camarasaurus (USNM 13786); (e) Cedarosaurus (FMNH PR 977, reversed from D’Emic[32]); (f) Epachthosaurus (UNPSJB-PV 920, redrawn and modified from Martínez et al.[22]); (g) Notocolossus; (h) Opisthocoelicaudia (ZPAL MgD-I-48). Note near-progressive decrease in total number of pedal phalanges and trend toward phalangeal reduction on pedal digits II–V throughout sauropod evolutionary history (culminating in phalangeal formula of 2-2-2-1-0 [seven total phalanges per pes] in the latest Cretaceous derived titanosaur Opisthocoelicaudia). Abbreviation: Mya, million years ago. Institutional abbreviations see Supplementary Information. (González Riga et al. 2016: figure 5)

As for the estimated mass of Notocolossus, González Riga et al. (2016) did their due diligence. The sections on mass estimation in the main text and supplementary information are very well done – lucid, modest, and fair. Rather than try to summarize the good bit, I’ll just quote it. Here you go, from page 7 of the main text:

The [humeral] diaphysis is elliptical in cross-section, with its long axis oriented mediolaterally, and measures 770 mm in minimum circumference. Based on that figure, the consistent relationship between humeral and femoral shaft circumference in associated titanosaurian skeletons that preserve both of these dimensions permits an estimate of the circumference of the missing femur of UNCUYO-LD 301 at 936 mm (see Supplementary Information). (Note, however, that the dataset that is the source of this estimate does not include many gigantic titanosaurs, such as Argentinosaurus[5], Paralititan[16], and Puertasaurus[11], since no specimens that preserve an associated humerus and femur are known for these taxa.) In turn, using a scaling equation proposed by Campione and Evans[20], the combined circumferences of the Notocolossus stylopodial elements generate a mean estimated body mass of ~60.4 metric tons, which exceeds the ~59.3 and ~38.1 metric ton masses estimated for the giant titanosaurs Dreadnoughtus and Futalognkosaurus, respectively, using the same equation (see Supplementary Information). It is important to note, however, that subtracting the mean percent prediction error of this equation (25.6% of calculated mass[20]) yields a substantially lower estimate of ~44.9 metric tons for UNCUYO-LD 301. Furthermore, Bates et al.[21] recently used a volumetric method to propose a revised maximum mass of ~38.2 metric tons for Dreadnoughtus, which suggests that the Campione and Evans[20] equation may substantially overestimate the masses of large sauropods, particularly giant titanosaurs. Unfortunately, however, the incompleteness of the Notocolossus specimens prohibits the construction of a well-supported volumetric model of this taxon, and therefore precludes the application of the Bates et al.[21] method. The discrepancies in mass estimation produced by the Campione and Evans[20] and Bates et al.[21] methods indicate a need to compare the predictions of these methods across a broad range of terrestrial tetrapod taxa[21]. Nevertheless, even if the body mass of the Notocolossus holotype was closer to 40 than 60 metric tons, this, coupled with the linear dimensions of its skeletal elements, would still suggest that it represents one of the largest land animals yet discovered.

So, nice work all around. As always, I hope we get more of this critter someday, but until then, González Riga et al. (2016) have done a bang-up job describing the specimens they have. Both the paper and the supplementary information will reward a thorough read-through, and they’re free, so go have fun.


I was a bit disappointed to hear David Attenborough on BBC Radio 4 this morning, while trailing a forthcoming documentary, telling the interviewing that you can determine the mass of an extinct animal by measuring the circumference of its femur.

We all know what he was alluding to, of course: the idea first published by Anderson et al. (1985) that if you measure the life masses of lots of animals, then measuring their long-bone circumferences when they’ve died, you can plot the two measurements against each other, find a best-fit line, and extrapolate it to estimate the masses of dinosaurs based on their limb-bone measurements.


This approach has been extensively refined since 1985, most recently by Benson et al. (2014). but the principle is the same.

But the thing is, as Anderson et al. and other authors have made clear, the error-bars on this method are substantial. It’s not super-clear in the image above (Fig 1. from the Anderson et al. paper) because log-10 scales are used, but the 95% confidence interval is about 42 pixels tall, compared with 220 pixels for an order of magnitude (i.e. an increment of 1.0 on the log-10 scale). That means the interval is 42/220 = 0.2 of an order of magnitude. That’s a factor 10 ^ 0.2 = 1.58. In other words you could have two animals with equally robust femora, one of them nearly 60% heavier than the other, and they would both fall within the 95% confidence interval.

I’m surprised that someone as experienced and knowledgeable as Attenborough would perpetuate the idea that you can measure mass with any precision in this way (even more so when using only a femur, rather than the femur+humerus combo of Anderson et al.)

More: when the presenter told him that not all scientists buy the idea that the new titanosaur is the biggest known, he said that came as a surprise. Again, it’s disappointing that the documentary researchers didn’t make Attenborough aware of, for example, Paul Barrett’s cautionary comments or Matt Wedel’s carefully argued dissent. Ten minutes of simple research would have found this post — for example, it’s Google’s fourth hit for “how big is the new argentinian titanosaur”. I can only hope that the actual documentary, which screens on Sunday 24 January, doesn’t present the new titanosaur’s mass as a known and agreed number.

(To be clear, I am not blaming Attenborough for any of this. He is a presenter, not a palaeontologist, and should have been properly prepped by the researchers for the programme he’s fronting. He is also what can only be described as 89, so should be forgiven if he’s not quite as quick on his feel when confronted with an interviewer as he used to be.)

Update 1 (the next day)

Thanks to Victoria Arbour for pointing out an important reference that I missed: it was Campione and Evans (2012) who expanding Anderson et al.’s dataset and came up with the revised equation which Benson et al. used.

Update 2 (same day as #1)

It seems most commenters are inclined to go with Attenborough on this. That’s a surprise to me — I wonder whether he’s getting a free pass because of who he is. All I can say is that as I listened to the segment it struck me as really misleading. You can listen to it for yourself here if you’re in the UK; otherwise you’ll have to make do with this transcript:

“It’s surprising how much information you can get from just one bone. I mean for example that thigh bone, eight feet or so long, if you measure the circumference of that, you will be able to say how much weight that could have carried, because you know what the strength of bone is. So the estimate of weight is really pretty accurate and the thought is that this is something around over seventy tonnes in weight.”

(Note also that the Anderson et al./Campione and Evans method has absolutely nothing to do with the strength of bone.)

Also if interest was this segment that followed immediately:

How long it was depends on whether you think it held its neck out horizontaly or vertically. If it held it out horizontally, well then it would be about half as big again as the Diplodocus, which is the dinosaur that’s in the hall of the Natural History Museum. It would be absolutely huge.

Interviewer: And how tall, if we do all the dimensions?

Ah well that is again the question of how it holds its neck, and it could have certainly reached up about to the size of a four or five storey building.

Needless to say, the matter of neck posture is very relevant to our interests. I don’t want to read too much into a couple of throwaway comments, but the implication does seem to be that this is an issue that the documentary might spend some time on. We’ll see what happens.


Well, who knew? There I was posting images of “Pelorosaurusbecklesi‘s humerus, radius and ulna, and skin impression. There I was saying that this beast is due a proper description, and warrants its own generic name. And what should come out today but a new paper by Paul Upchurch, Phil Mannion and, oh yes, me, which does exactly that.

Screen Shot 2015-06-03 at 19.05.12

The headline news is the long-overdue establishment of a new genus name for this species — something that we’ve known was needed at least since Upchurch’s (1993) dissertation. Paul and Phil came up with the name Haestasaurus, from “Haesta”, the name of the putative pre-Roman chieftain whose people apparently settled the area of Hastings and gave the town its name. It’s nice that I can finally stop typing the scare-quotes around the no-longer-relevant old genus name “Pelorosaurus“!

Upchurch et al. 2015: figure 2. Left humerus of Haestasaurus becklesii (NHMUK R1870). A, anterior view; B, posterior view; Abbreviations: af, anconeal fossa; dp, deltopectoral crest; hh, humeral head; ltf, lateral triceps fossa; mtf, medial triceps fossa.

Upchurch et al. (2015: figure 2). Left humerus of Haestasaurus becklesii (NHMUK R1870). A, anterior view; B, posterior view; Abbreviations: af, anconeal fossa; dp, deltopectoral crest; hh, humeral head; ltf, lateral triceps fossa; mtf, medial triceps fossa.

(As you can see, the photography is rather better than in my own illustrations, which I made independently some years ago.)

Of course Paul has had an eye on this work, on and off, since the early 1990s. Then in the late 2000s, when I was working on Xenoposeidon and other Wealden sauropods, I started work independently on a redescription — which of course is why I prepared the figures that have appeared in the last few posts. But that work petered out as I started working more on other specimens and on the problems of the sauropod neck. More recently, Paul and Phil hunkered down and got the nitty-gritty descriptive work done.

Once they had a complete draft manuscript, they very graciously invited me onto the authorship — not something they had to do, but they chose to based on my previous interest in the specimen. My contribution was minor: I provided two of the illustrations, tidied up the early versions of several others, and did an editing pass on the text.

Upchurch et al. (2015: figure 1). Map showing England and Wales, with boundaries for English counties. The magnified inset shows the Isle of Wight and East and West Sussex in more detail, marking the positions of selected major towns/cities and the fossil localities mentioned in the main text. Based on

Upchurch et al. (2015: figure 1). Map showing England and Wales, with boundaries for English counties. The magnified inset shows the Isle of Wight and East and West Sussex in more detail, marking the positions of selected major towns/cities and the fossil localities mentioned in the main text. Based on “English ceremonial counties 1998” by Dr. Greg, CC By-SA 3.0.

(This map is one of the two illustrations that I provided; the other is the multi-view photograph of the Pelorosaurus conbeari humerus.)

I’m grateful to Paul and Phil, both for inviting me onto this project, and for taking into account my strong preference for an open-access venue. It’s largely because of the latter that the paper now appears in PLOS ONE, where the glorious colour illustrations appear at full resolution and may be re-used for any purpose subject to attribution.

So: what actually is Haestasaurus? Is it the early titanosaur that we’ve all been assuming? The unexciting answer is: we don’t really know. Our paper contains three phylogenetic hypotheses (all of them Paul and Phil’s work, I can’t take any credit). These results are from adding Haestasaurus to the Carballido and Sander (2014) matrix, to the Mannion et al. (2013) standard discrete matrix and to the Mannion et al. (2013) continuous-and-discrete matrix. Only the last of these recovers Haestasaurus as a titanosaur — as sister to Diamantinasaurus and then Malawisaurus, making it a lithostrotian well down inside Titanosauria.

Both both of the other analyses find Haestasaurus as a very basal macronarian — outside of Titanosauriformes. Here is the result of the analysis based on Carballido and Sander’s Europasaurus matrix:

Upchurch et al. (2105: figure 15). Strict consensus tree (CSM). A strict consensus tree based on the 28 most parsimonious trees generated by analysis of the Carballido and Sander [19] data matrix with the addition of Haestasaurus and six new characters (Tendaguria excluded a priori). GC values (multiplied by 100) are shown in square brackets for all nodes where these values are greater than 0. The monophyletic Diplodocoidea has been collapsed to a single branch in order to reduce figure size. Abbreviation: Brc, Brachiosauridae.

Upchurch et al. (2105: figure 15). Strict consensus tree (CSM). A strict consensus tree based on the 28 most parsimonious trees generated by analysis of the Carballido and Sander [19] data matrix with the addition of Haestasaurus and six new characters (Tendaguria excluded a priori). GC values (multiplied by 100) are shown in square brackets for all nodes where these values are greater than 0. The monophyletic Diplodocoidea has been collapsed to a single branch in order to reduce figure size. Abbreviation: Brc, Brachiosauridae.

As you can see, Haestasaurus is here a camarasaurid, making it (along with Camarasaurus itself) the most basal of all macronarians. In the second analysis — the one using discrete characters only from Mannion et al.’s Lusotitan paper — Haestasaurus is again in the most basal macronarian clade, but this time as sister to Janenschia and then Tehuelchesaurus. (In this topology, Camarasaurus is the next most basal macronarian after that three-taxon clade.)

So it looks like Haestasaurus is either a very basal macronarian or a pretty derived titanosaur. We don’t know which.

But, hey, at least it has a proper name now!


It’s Matt’s birthday today. I’d like to dedicate a sauropod to him, but I don’t have the authority to do that. So instead, I dedicate this blog-post to him, and declare it the Mathew J. Wedel Memorial Blog Post.


Yesterday, we looked at (mostly) the humerus of the Wealden sauropod “Pelorosaurusbecklesii, which you will recall is known from humerus, radius, ulna and a skin impression, and — whatever it might be — is certainly not a species of Pelorosaurus.

Now let’s look at the radius and ulna.

Left forearm of

Left forearm of “Pelorosaurusbecklesii holotype NHMUK R1870, articulated, in anterior view, with proximal to the left: radius in front, ulna behind.

They fit together pretty neatly: the proximal part of the radius is a rounded triangular shape, and it slots into the triangular gap between the anteromedial and anterolateral processes of the proximal part of the ulna.

Left forearm of “Pelrosaurus” becklesii holotype NHMUK R1870 in proximal view, with anterior to the right. The arms of the ulna enclose the radius.

Left forearm of “Pelorosaurusbecklesii holotype NHMUK R1870 in proximal view, with anterior to the right. The “arms” of the ulna enclose the radius.

Let’s take a closer look at the ulna:

Left ulna of

Left ulna of “Pelorosaurusbecklesii holotype NHMUK R1870. Top row: proximal view, with anterior to the bottom. Middle row, from left to right: medial, anterior, lateral and posterior views. Bottom row: distal view, with anterior to top.

And the radius:

Left radius of

Left radius of “Pelorosaurus” becklesii holotype NHMUK R1870. Top row: proximal view, with anterior to the bottom. Middle row, from left to right: medial, anterior, lateral and posterior views. Bottom row: distal view, with anterior to top.

As you can see, it’s pretty well preserved: there’s no evidence of significant crushing in any of the bones, and the 3d shape is apparent.

In short, it’s a really sweet specimen. Someone really ought to get around to describing it properly, and giving it the new generic name that it clearly warrants.