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Raptor Red and Heyday Of The Giants
Thomas R. Holtz, Jr. wrote:
Here's a blast from the past (nearly 10 years old) in the archives:
To quote from the piece: "Curiously out of place are the unnamed diplodocid
(at least Bakker now
recognizes that they did make it into the Cretaceous),"
I metion this not to make HP Holtz look foolish (I swear!), but this line
got me thinking. I don't think there are any Cretaceous diplodocoids from
North America. AFAIK, the only sauropods from this time and place are all
titanosauriforms. The alleged diplodocid from the Early Cretaceous of North
America may be based on neck vertebrae that were provisionally referred to
_Barosaurus_, but are now assigned to _Sauroposeidon_.
Which leads me to...
Mickey Mortimer wrote:
Bruhathkayosaurus is Maastrichtian. Then there's the huge
Kimmeridgian-Tithonian Morrison diplodocids, and the large Early Jurassic
Moroccan femur and footprints...
_Sauroposeidon_ is another huge mid-Cretaceous sauropods; and it had a close
relative across the Pond, known from a single neck vertebra
("Angloposeidon", from the Isle of Wight).
To emphasize Mickey's point, really big sauropods appear to have existed
from the mid-Jurassic onwards. The Morrison Formation does appear to have
had more than its fair share - although the size estimates for some of these
sauropods have been significantly downsized since their original
descriptions (e.g., "Ultrasaurus", _Seismosaurus_). _Amphicoelias
fragillimus_ may have been enormous; but it's based on a single dorsal
vertebra that is now lost.
Also, don't forget that diplodocids might have been very long, but they were
also very lightly built. A large portion of the length was made up of the
very long neck and the even longer whiplash tail. The heaviest (most
massive) dinosaurs were the titanosauriforms, including brachiosaurids.
Although huge brachiosaurids and titanosaurians are known from the Early
Cretaceous, some impressively-sized titanosaurians are also known from the
Late Cretaceous, including _Pelligrinisaurus_ and "_Antarctosaurus_"
David Marjanovic wrote:
The footprints from Morocco called *Breviparopus* are Middle Jurassic,
Yep, the ichnotaxon _Breviparopus taghbaloutensis_ comes from the Middle
Jurassic (Bathonian) of the High Atlas Mountains.
A 2.36m long sauropod femur has been described from the Middle Jurassic of
Morocco (Charroud and Fedan, 1992). In their description of _Atlasaurus_
(also from the Middle Jurassic of Morocco), Monbaron et al. (1999) mention
this huge femur and suggest that it may belong to the same sauropod that
produced the _Breviparopus_ footprints.
The Cenomanian may well have been an interesting time for sauropods, but
without a better Albian and Turonian record it's difficult to make
True. The Aptian/Albian does appear to have been produced some very large
sauropods (e.g., _Sauroposeidon_, "Hughenden sauropod"), but most are very