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Re: Amazing Tendaguru and the most prolific localities in the world

Sorry for the delay in replying to this.  It took me a while to gather
the information you asked for on the SII mount (which I now see was in
a different message from the one I'm replying to, but I'll include in
anyway as I'm not sure where that other message has got to.)

> Date: Fri, 13 May 2005 12:19:17 -0500
> From: Tim Williams <twilliams_alpha@hotmail.com>
>>> Firstly, the combination of features seen in the skull is
>>> consistent with a primitive titanosauriform.  I very much doubt
>>> that the skull belongs to a diplodocoid, or even a basal
>>> macronarian.
>> Remind me, how much material do we have that shows us the
>> differences between the skulls of basal Macronarians and basal
>> Titanosauriforms?
> Well, according to Upchurch et al. (2004) in Dinosauria II,
> _Bellusaurus_, _Atlasaurus_ and _Jobaria_ are all basal
> macronarians, and we have cranial material for all three (especially
> _Jobaria_).

Ye-es.  But that bit of the tree, round about the base of
Neosauropoda, is pretty messy and prone to change between analyses, as
the ever-changing positions of _Haplocanthosaurus_ illustrate.  I
wouldn't want to wager the life of my firstborn on _Jobaria_ coming
out in the same place in the next published analysis.

> As for basal titanosauriforms, the only good skull material I can
> think of comes from _Brachiosaurus brancai_ and the putative
> _Brachiosaurus_ skull from Felch Quarry.

QED.  We're working from a sample-size (once we remove the two
specimens in question) of zero.

>> Not much.  From a quick re-skim of Salgado and Calvo 1997, in fact,
>> I am tempted to say "none at all".
> The fossil record has been kind to us since then and offered us
> _Jobaria_, which comes with a pretty skull intact.

OK.  We'll see about Jobaria when the great and glorious day that
something gets published on it other than Sereno et al. 1999, which
you will recall describes not only _Jobaria_ but also _Nigersaurus_,
and gives them maybe one page each in a paper that is more interested
in uneven evolutionary rates.  Basically, what's been published on Big
J. so far amounts to not much more than a press-release.  I assume
that Jeff Wilson is still working away on it (can anyone confirm or
deny?) but AFAIK there is no publication on the horizon six years
after the initial Act Of Taxonomy.

>> The best _B. brancai_ dorsal sequence is probably that of HMN SII,
>> consisting of D1, D2 and the anterior part of D3, all lost; plus
>> D4, D7 and a D10/D11 pair --but of course those position
>> assignments are pretty much guesswork, especially as you get
>> further back.
> The HMN SII specimen of _B. brancai_ included an almost complete
> presacral vertebral series, according to Heinrich's taphonomic paper
> (which was based on Janensch's original field notes).  Either the
> completeness of the presacral column is exaggerated, or certain
> vertebrae from HMN SII were lost or destroyed, and no casts made.

Very interesting!  I do not have this Heinrich taphonomic paper of
which you speak (reference, please!) but I notice that Christian and
Heinrich's 1998 paper on _Brachiosaurus_ neck posture mentions in

        Skeleton S II, excavated between 1909 and 1911 (Janensch
        1914a) supplied parts of the skull, the fairly complete
        presacral vertebral column (11 cervicals, 11 dorsals) [...]
        (Janensch 1929)

So it's exciting to think there might be more evidence out there than
I'd realised.  The thing to do, of course, would be to read Janensch
1929; but for some obscure reason, Janensch chose to obscure his
research by writing all his papers in German.

My own assertions on the SII dorsal material are based on (A) what
Janensch (1950) figured; and (B) what I actually saw while at the
Humboldt Museum in March.  All they could find in the way of SII
dorsals ("they" being my very helpful hosts David Unwin and
Wolf-Dieter Heinrich) was:
        D4 (as figured in Janensch 1950, Abh. 53-54)
        D?7 (Janensch 1950, Abh. 56-57)
        D10+D11 (Janensch 1950, Abh. 62-64)
(Also cervicals 3-9 but not 10-13; 1 and 2 were never found.)

And now, *drum roll* the composition of the SII mount (as it was until
a month or so ago -- of course they may use different material when
they re-mount it, but I don't see why they should.  If David Unwin is
reading this, perhaps he'll comment.)

Christian and Heinrich 1998 is the best English-language reference I
have for this, and it reads as follows:

        The interpretation is based on a skeleton of _Brachiosaurus
        brancai_ mounted for display at the Belin Museum of Natural
        History.  The skeleton is a composite of original bones,
        copies of bones, and plaster reconstructions of missing parts
        (Janensch 1938, 1950b).  The skeletal remains of
        _Brachiosaurus brancai_ were excavated during the German
        Tendaguru Expedition between 1909 and 1912 (Janensch 1914a).
        They have been recovered from the Upper Jurassic Middle and
        Upper Saurian Beds of the Tendaguru Series exposed at
        different sites in the surroundings of the Tendaguru Hill in
        southeastern Tanzania, East Africa.  The age of the Middle and
        Upper Saurian Beds has been much disputed.  Today the age of
        both dinosaur-bearing beds is commonly considered Kimmeridgian
        to Tithonian (e.g. Aitken 1961, Russell et al. 1980), however,
        the precise age determination requires further investigation.
        The mounting was directed by W. Janensch and finished in 1937.
        The skeleton was disassembled during World War II and
        remounted in 1952.

        The major part of the composite skeleton belongs to one single
        individual of _Brachiosaurus brancai_, the so-called specimen
        S II.  it is an incomplete skeleton which was recovered from
        the Middle Saurian Bed at Site S, located about 1 km south of
        the Tendaguru Hull (Janensch 1914a, b).  Skeleton S II,
        excavated between 1909 and 1911 (Janensch 1914a) supplied
        parts of the skull, the fairly complete presacral vertebral
        column (11 cervicals, 11 dorsals), cervical and trunk ribs,
        most of the anterior appendicular skeleton (e.g. both sternal
        plates and coracoids, left shoulder blade, right anterior
        limb, left humerus, ulna and radius), parts of the pelvis
        (e.g. both pubes), and incompletely preserved hind libs, among
        them the fragmentary right femur, tibia, fibula, and badly
        preserved hind foot bones (Janensch 1929).  Most of the
        preserved cervical series was originally found in natural
        articulation, except for cervical 8 and some cervical ribs
        recovered as separate elements (Janensch 1914b).  The majority
        of the dorsal vertebrae were disarticulated.  The tail was
        already missing when the specimen was discovered, possibly due
        to erosion (Janensch 1914b).  The taphonomic evidence suggests
        maceration and decay of the carcass prior to burial.  With
        only a few exceptions, the bones were disarticulated but
        associated.  Not all parts of skeleton S II are well
        preserved, however, the shape of most bones has not been
        substantially changed by taphonomic or diagenetic processes.

        A second specimen of _Brachiosaurus brancai_ (S I) which was
        also recovered from the Middle Saurian Bed at Tendaguru site S
        yielded additonal material not represented in specimen S II
        (e.g. braincase, axis).

        Skeleton S II provided the bulk of the bones, however, only
        some of them could be included in the mount.  The skull, the
        cervical and dorsal vertebrae had to be replaced by plaster
        reconstruction due to their extreme fragility (Janensch
        1950b).  The right shoulder blade, some bones of the left
        manus, four trunk ribs, and the left ischium are also plaster
        reconstructions.  They have been modelled from existing
        counterparts of the other body side (Janensch 1950b).

        Some missing elements of skeleton S II either have been
        substituted by bones of other specimens of the same species
        and size or by plaster reconstructions.  Other missing items
        have been replaced by bones or copies of bones from
        different-sized specimens, also of the same species.

        Most important for this study is the preservation of the
        vertebral centra and the spinal processes of the cervical
        vertebrae of skeleton S II.  According to Janensch (1950a),
        there are 13 cervicals in _Brachiosaurus brancai_.  Centra and
        spinal processes are preserved in the cervicals 3 to 5 and 8.
        The spinal processes of all other cervicals are reconstructed.
        The centra of cervicals 9 to 13 are preserved.  The axis is
        well preserved in skeleton S I but completely reconstructed in
        skeleton S II.

        A fairly complete caudal series of 50 vertebrae recovered from
        the Upper Saurian Bed at Tendaguru site "no" has been
        installed as the tail of the skeleton (Janensch 1950a, b).
        Its size seems to correspond well to main skeleton S II
        (Janensch 1950 b).  The missing first caudal vertebra and most
        of the haemopophyses are plaster reconstructions.  At the end
        of the tail a few small pieces also modelled in plaster were

        In addition, a left femur and a left zygopodium (tibia,
        fibula) have been included in the skeletal reconstruction.
        They have been obtained from the Middle Saurian Bed exposed at
        Tendaguru localities "Ni" and "Bo".  The left tibia and fibula
        from site "Bo" are of the same size as the installed right
        tibia and fibula of specimen S II (Janensch 1950b).  In
        contrast to that, the involved left femur from locality "Ni"
        is slightly shorter than the installed right thigh bone of
        specimen S II.  The pelvis of specimen S II has suffered
        damage, particularly to the ilia and ischia.  Therefore, a
        right ilium from the Midle Saurian Med (site "Ma") as well as
        an incomplete right ischium obtained from the Upper Saurian
        Bed (site "L") have been included in the skeleton
        reconstruction (Janensch 1950b).  Both pubes are originals of
        the specimen S II.  The sacrum was modelled in plaster after
        partial skeleton "Aa" from the Middle Saurian Bed and partial
        skeleton "T" recovered from the Upper Saurian Bed (Janensch

        The right forefoot is a fairly complete original of skeleton S
        II (Janensch 1922, 1950b, 1961), the left modelled in plaster.
        Like the left forefoot, most hind foot elements are plaster
        reconstructions.  The reconstruction of the hind foot skeleton
        is mainly based on bones from Tendaguru site "Bo" as well as
        badly preserved metatarsals and phalanges from specimen S II
        (Janensch 1950b).  Only a few pes phalanges have been
        reconstructed without Tendaguru counterparts.

Gunga et al. 1999, contains a shorter summary that is entirely in
accordance with this.  I believe Gunga et al. 1995 also has something
to say on the subject of the composition of the SII mount, but I
can't find my copy of that at present.

The only dissent comes from Paul 1988, which says:

        The Berlin mount, HMN SII, is a composite made of different
        sized individuals, plus some bones modelled in plaster.
        Janensch's restoration of SII is schematic and includes
        postural and proportional errors.
        The basis for the skeletal restoration in Fig. 1 is the
        holotype and best specimen, and the one on display in Berlin,
        HMN SII.  This individual includes a partial skull (S116, in
        Janensch, 1935-36), all but the first three neck vertebrae,
        dorsal vertebrae 1-4, 8?, 10-12 and parts of others, most of
        the dorsal ribs, a sternal, scapular material, a coracoid, a
        complete forelimb and hand, the pubes, a partial femur, a
        fibula, and hindfoot bones. [...] The HMN specimens figured by
        Janensch (1950a, 1961) provide virtually all the rest of the
        missing elements, including a hip, sacrum and tail (HMN Aa).
        Only a few hindfoot bones are absent.
        The new restoration has a scaled up HMN Aa tail that is longer
        than it is in the mount.
        [but C&H says it's the right size (and not from Aa).

This differs from Christian and Heinrich's catalogue in several
important respects:

* Paul helpfully identifies a separate specimen number that has
  apparently been assigned to the skull of the SII individual.
* Paul claims that the first three neck vertebrae are missing (but
  this I know to be a mistake, as C3 is both figured in Janensch 1950
  and on display in a non-public gallery).
* Paul claims that only seven of the dorsals are known; this tallies
  with both Janensch 1950's figures and my own observations, but
  disagrees with Christian and Heinrich 1998 and with the Heinrich
  taphonomy paper you mentioned.
* Paul says that only one sternal and one coracoid are preserved;
  Christian and Heinrich say that both of each are present in the
* Paul implies that no tibia is known from SII, but Christian and
  Heinrich say that the right tibia is known along with its fibula.
* Paul says that the tail is that of specimen Aa.  But Christian and
  Heinrich say that the tail is from site "no" in the Upper Saurian
  Bed (they do not provide a specimen number) whereas Aa is from the
  Middle Saurian Bed.  Their only mention of specimen Aa is that the
  sacrum of the SII mount is modelled after it.
* Paul claims that the tail is too small for the rest of the mount,
  but Christian and Heinrich say that "its size seems to correspond
  well to main skeleton S II".

I'll welcome any clarification that anyone can provide on these points
of disagreement.


Christian, Andreas, and Wolf-Dieter Heinrich.  1998.  The neck posture
of _Brachiosaurus brancai_.  _Mitteilungen aus dem Museum fur
Naturkunde, Berlin, Geowissenschaften, Reihe, 1, p73-80 (German sum.)

Gunga, H. C., K. A. Kirsch, F. Baartz, L. Rocker, W.-D. Heinrich,
W. Lisowski, A. Wiedemann and J. Albertz.  1995.  New Data on the
Dimensions of Brachiosaurus brancai and Their Physiological
Implications.  Naturwissenschaften 82: 190-192.

Gunga, H. C., K. A. Kirsch, J. Rittweger, A. Clarke, J. Albertz,
A. Wiedemann, S. Mokry, T. Suthau, A. Wehr, W.-D. Heinrich and
H.-P. Schulze.  1999.  Body Size and Body Volume Distribution in Two
Sauropods from the Upper Jurasic of Tendaguru (Tanzania).
Mitteilungen des Museums fur Naturkunde Berlin, Geowissenschaftliche
Reihe 2: 91-102.

Janensch, W.  1929a.  Material und Formengehalt der Sauropoden in der
Ausbeute der Tendaguru-Expedition.  Palaeontographica (Suppl. 7)

Janensch, W. (1950a). Die Wirbelsaule von _Brachiosaurus
brancai_. Palaeontographica (Suppl. 7) 3: 27-93.

Paul, G. S. 1988. The brachiosaur giants of the Morrison and Tendaguru
with a description of a new subgenus, Giraffatitan, and a comparison
of the world's largest dinosaurs.  Hunteria 2 (3): 1-14.

Sereno, Paul C., Allison L. Beck, Didier. B. Dutheil, Hans
C. E. Larsson, Gabrielle. H. Lyon, Bourahima Moussa, Rudyard
W. Sadleir, Christian A. Sidor, David J. Varricchio, Gregory P. Wilson
and Jeffrey A. Wilson.  1999.  Cretaceous Sauropods from the Sahara
and the Uneven Rate of Skeletal Evolution Among Dinosaurs.  Science,
vol. 282, pp. 1342-1347;

 _/|_    ___________________________________________________________________
/o ) \/  Mike Taylor  <mike@miketaylor.org.uk>  http://www.miketaylor.org.uk
)_v__/\  "I think it's too consistently wrong not to be fixable" --
         Phil Baldwin.

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