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An unusual new neosauropod dinosaur from the Lower Cretaceous Hastings Beds Group of

East Sussex, England

Michael P. Taylor and Darren NaishSchool of Earth and Environmental Sciences

University of PortsmouthPortsmouth PO1 3QL

<[email protected]>

An unusual new neosauropod dinosaur from the Lower Cretaceous Hastings Beds Group of

East Sussex, England

Michael P. Taylor and Darren NaishSchool of Earth and Environmental Sciences

University of PortsmouthPortsmouth PO1 3QL

<[email protected]>

freaky

Where to discover new dinosaurs (I)

Mike Benton at SVPCA 2005suggested countries such asMongolia and Argentina ...

Where to discover new dinosaurs (II)... but the best unexplored territory is stillthe basement of the Natural History Museum.

Meet BMNH R2095

A single, partial mid-to-posterior dorsal vertebra.

That's not much material, but:

Sauropod dorsals are very diagnostic.

This specimen is highly apomorphic.

Briefly described by Lydekker(1893) when no-one knewanything about sauropods.

Subsequently overlooked.

Where it's fromPrecise locality information is not preserved (if it was ever recorded).Lydekker (1893) just said “from the Wealden of Hastings”.

But: known to have been collected by Rufford.Better documented Rufford specimens are known to be from

East Cliff and Ecclesbourne Glen (both east of Hastings)

R2095

Age

Stratigraphic information is not preserved.

Units exposed both East Cliff andEcclesbourne Glen are part of theAshdown Beds Formation

R2095 probably from Ecclesbourne Glen: It is closer to Hastings than is East Cliff Most of Rufford's specimens are from Ecclesbourne Glen.

Ashdown Beds Formation exposure atEcclesbourne Glen is Berriasian

R2095

A long-overdue closer look at the specimen

Left and right lateral

200 mm

Anterior

A long-overdue closer look at the specimen

Anterior and posterior

So what is it?

So what is it? 1. Sauropoda

So what is it? 2. Eusauropoda

So what is it? 3. Neosauropoda

So what is it? 4. a unique Neosauropod

Similarities between sides

Similarities and differences between sides

Reconstruction

Parapophysis can beidentified at junction oflaminae.

Positions of diapophysisand zygapophyses can bededuced from trajectoriesof laminae.

Condyle curvatureinferred from cotyle.

High location of parapophysisindicates posterior position.

So what kind of Neosauropod is it?

“Classic” diplodocoids(Diplodocidae+ Dicraeosauridae)

Rebbachisauridae

Titanosauria

Brachiosauridae

Camarasauridae ??Diplodoco

idea

Macronaria

Ne

osa

uro

pod

a

Is it a classic diplodocoid?Diplodocus carnegii holotype CM 84, dorsal 8(Hatcher 1901, Plate VII, reversed)

Is it a rebbachisaur?Rebbachisaurus garasbae holotype, posteriordorsal (photo by Fabio Dalla Vecchia, reversed)

Is it a rebbachisaur?Rebbachisaurus garasbae holotype, posteriordorsal (photo by Fabio Dalla Vecchia, reversed)

Laterally diverging prezygapophyses

Prezygapophyses close together

Is it a camarasaur?Camarasaurus grandis holotype YPM 1901,posterior dorsal (Ostrom & McIntosh 1966, Plate 25)

Is it a camarasaur?Camarasaurus grandis holotype YPM 1901,posterior dorsal (Ostrom & McIntosh 1966, Plate 25)

Stupid

and

ugly

Stupid

and

ugly

Is it a brachiosaur?Brachiosaurus brancai holotype HMN SII, D7(Janensch 1950, Figure 56, reversed)

Is it a brachiosaur?Brachiosaurus brancai holotype HMN SII, D7(Janensch 1950, Figure 56, reversed)

??

??

Is it a titanosaur?Neuquensaurus autralis MCS-5/20-22, D9(Salgado et al. 2005, Figure 4)

Is it a titanosaur?

Internalstructurecamerate

Camellate

Neuquensaurus autralis MCS-5/20-22, D9(Salgado et al. 2005, Figure 4)

So what is it?

So what is it?

It seems to represent a completely new group(or a very highly derived member of a known group)

... what we used to call a new “family”

Centrum proportions are similar to Brachiosaurus brancai holotype HMN SII, D7

B. brancai is estimated 25m long (Paul 1988)If isometrically similar, R2095 would be 15m.

B. brancai is estimated 35000 kg (average ofseveral sensible published estimates). R2095 would be 7500 kg.

(About the mass of a big elephant)

How big was R2095?

Longer and lighter if similar to Diplodocus carnegii CM 84

D. carnegii is 27m long and 1200 kg (Wedel 2005).

Centrum proportions differ, so:– assume length proportional to centrum length

=> R2095 is 20m long

– assume mass propotional to centrum length x cotyle height x width=> R2095 masses 2300 kg

How big was R2095?

“Pelorosaurus” becklesi (actually generically distinct and titanosaurian)

Sauropods of the Hastings Beds Group

Humerus Ulna

Radius

“Cetiosaurus” brevis = Pelorosaurus conybeari (pending ICZN petition)

Humerus

Sauropod diversity goes nuts!

Dorsal vertebrae of Tendaguria tanzaniensis holotype MB.R.2092.1-2, NB4, NB5(Bonaparte, Heinrich and Wild 2000)


Agustinia ligabuei Bonaparte 1999Reconstruction by Mudyryknow J.R., from The Dinosauriconhttp://dino.lm.com/images/display.php?id=2268

It might be some kind of titanosaur ...

http://dino.lm.com/images/display.php?id=2268


Agustinia ligabuei Bonaparte 1999Reconstruction by Mudyryknow J.R., from The Dinosauriconhttp://dino.lm.com/images/display.php?id=2268

It might be some kind of titanosaur ...

... but Titanosauria is the new Cetiosauridae

http://dino.lm.com/images/display.php?id=2268

I'd like to thank everyone who'smade tonight possible ...

* My co-author Doctor Darren Naish* Philip James Rufford for finding and donating the specimen* Everyone who's ignored it for 113 years* Sandra D. Chapman (Natural History Museum) for access to the specimen.* Nick Pharris (University of Michigan) for etymological assistance.* We used English translations of several papers from the very useful Polyglot Paleontologist web-site

http://ravenel.si.edu/paleo/paleoglot/index.cfm

Thanks are due specifically to the following translators:* Sebastián Apesteguía (Bonaparte 1999a),* Matthew T. Carrano (Bonaparte 1986b),* William R. Downs (Young and Zhao 1972),* Matthew C. Lamanna (Bonaparte and Coria 1993, del Corro 1975 and Lavocat 1954)* Jeffrey A. Wilson (Salgado and Coria 1993).

* In addition, portions of Janensch 1914 were translated by Gerhard Maier.* David M. Martill (University of Portsmouth) reviewed the manuscript.* Mathew J. Wedel (UCMP) reviewed this presentation.

http://ravenel.si.edu/paleo/paleoglot/index.cfm