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

Mike Taylor wrote:

Sorry for the delay in replying to this.  It took me a while to gather
the information you asked for on the SII mount


No problem - it was well worth the wait.

Anyways...

From Christian and Heinrich (1998)... 

        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 femur from SII is incomplete. Heinrich (1999) estimates a total length of 1960 mm for the femur, which makes it shorter than the SII humerus (2130 mm, which is complete). Thus the humerus would appear to be longer than the femur, as in _B. altithorax_ (in which the humerus is only slightly longer than the femur). However, because the SII femur is incomplete, we cannot ascertain the exact humerofemoral ratio for SII. Do you have lengths for (a) the *restored* femur of the mounted specimen SII and (b) the femur from locality "Ni"?

In any case, it appears that the mounted skeleton is not only a composite of several comparably-sized individuals, but made up of individuals from <different horizons>. Brachiosaur elements from both the Middle and Upper Saurian Beds went into making the mounted skeleton. Can we be 100% certain that the brachiosaur specimens from both horizons (Middle and Upper Saurian Beds) come from the SAME species?

(To complicate matters further, alleged _B. brancai_ material is also reported from a THIRD Tendaguru horizon: the "Transitional Sands between _Trigonia smeei_-Bed and the upper Saurian Bed" (Heinrich, 1999)).

* 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).

Hmm... both SI and SII have many cervicals preserved (six and eleven, respectively) (Heinrich, 1999).

* 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.

Yes, Heinrich (1999) says that ELEVEN dorsals are known for SII. Of course, I don't know how many were actually excavated.

* Paul says that only one sternal and one coracoid are preserved;
  Christian and Heinrich say that both of each are present in the
  mount.

Heinrich (1999) says that a scapula, coracoids and sternals are present in SII.

* Paul implies that no tibia is known from SII, but Christian and
  Heinrich say that the right tibia is known along with its fibula.


Ditto for Heinrich (1999) - which makes sense.

* 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".

This may be a judgement call, considering that the tail of SII is not actually preserved. Apparently Tendaguru site "D" has nearly 30 _B. brancai_ caudals, as part of a multi-taxon assemblage that includes a medium-sized individual of _B. brancai_.

Cheers

Tim