Brachiosauridae

    Brachiosauridae, as I have it here, may not really exist.  It may just be a collection of basal titanosauriforms thrown together without respect for true characteristics. However, I believe Brachiosauridae may have merit. Here it consists of a poorly-constrained group of similar forms, known for their long necks and long arms. The two best-known brachiosaurids are Brachiosaurus and Giraffatitan, and as such most representations of the group will be based on them. This leads to mistakes, like making every stegosaurid look like the unique Stegosaurus. Generally, brachiosaurids have long arms relative to the hindlimbs and very long, somewhat vertically directed necks.

<--Brachiosauridae
      |--Europasaurus
      `--+--Giraffatitan
           `--+--Brachiosaurus
                `--+--Abydosaurus
                     |--Cedarosaurus
                     `--Venenosaurus

Brachiosauridae:

Taxon or Taxa: Time/Place Comments:
Europasaurus holgeri Mateus, Laven, and Knötschke vide Sander, Mateus, Laven, and Knötschke 2006 middle Kimmeridgian (LJ) of Germany This is a dwarf macronarian from what were the islands of Europe (well, probably just one particular island, given how speciation happens on islands). It is known from 12 or more individuals of different ages and sizes (1.7-6.2 m long), and bone histology indicates that the large individuals were adults. Much of the skeleton is known, including at least one gorgeous skull that looks a bit like Brachiosaurus with a shorter snout and taller nasal arch.
This makes another case of island dwarfism among dinosaurs, the most famous being Magyarosaurus.
Giraffatitan brancai Olshevsky, 1991 (originally Brachiosaurus brancai Janensch, 1914) late Kimmeridgian-Tithonian (LJ) of Tanzania Originally considered to be a species of Brachiosaurus, Giraffatitan appears to deserve its own genus, as no derived characters have been found to link it to Brachiosaurus proper. The tallest skeleton of anything ever mounted is an honor belonging to this taxon, although the specimen is a composite and larger individuals are known. The skull has an unusually tall rounded crest containing the nostrils. This species is unusual in possessing "withers" over the shoulders.
Brachiosaurus altithorax Riggs, 1903 Kimmeridgian (LJ) of Colorado and Utah Less well-known than its African cousin Giraffatitan, this species is similar, but lacks among other things the "withers" found in the Tanzanian taxon. Most restorations of this species are based on Giraffatitan.
There is a Morrison skull, discovered back in the Marsh-Cope days (and incorporated by Marsh into his vision of "Brontosaurus"'s skull), that after further study has been shown to be brachiosaurid. It is intermediate in some features to Camarasaurus and Giraffatitan (such as length of the muzzle), and if it belongs to B. altithorax, it would constitute excellent evidence for separation of Brachiosaurus and Giraffatitan.
The famous Ultrasauros macintoshi Jensen, 1985, turned out to be based on a Supersaurus dorsal vert and a referred large Brachiosaurus shoulder blade.
Abydosaurus mcintoshi Chure, Britt, Whitlock, and Wilson, J. A., 2010 middle Albian (EK) of Utah Rather conveniently, Abydosaurus is known from excellent cranial remains, as well as some useful postcranial material. Usually, you get one or the other, with the postcranial stuff far more common unless you include teeth under the cranial heading (no pun intended). Abydosaurus was discovered within Dinosaur National Monument, and quite close to the old Visitor's Center as well; while you may know Dinosaur NM for its Morrison Formation dinosaurs, it also has a healthy supply of Cedar Mountain Formation material, and a variety of other fossiliferous formations. Abydosaurus is known from cranial remains of at least four individuals and some girdle bones, limb bones, and verts from the same quarry. The skull is like that of Giraffatitan except the teeth are narrower and the nasal arch is more subdued.
Its name is an involved allusion to Egyptian mythology: Abydos is a name for a city on the Nile where Osiris' head and neck were buried. The type locality for Abydosaurus overlooks a river, and the head and neck of the type individual were found there.
Cedarosaurus weiskopfae Tidwell, Carpenter, and Brooks, 1999 Barremian-early Aptian (EK) of Utah and early Albian (EK) of Texas A brachiosaurid from the Yellow Cat member of the Cedar Mountain Formation, this sauropod is known from a partial skeleton including vertebrae, partial girdles, and most of the limbs. Some remains referred to Texas "Pleurocoelus" belong here. It was a smallish sauropod.
Venenosaurus dicrocei Tidwell, Carpenter, and Meyer, 2001 mid Aptian (EK) of Utah Similar to the earlier sauropod Cedarosaurus from the Yellow Cat Member of the Cedar Mountain Formation, this seemingly small titanosauriform, from the Poison Strip Member, is based on vertebral and limb remains. Other material, including juvenile remains, may belong here.

Brachiosauridae i.s.:

Taxon or Taxa: Time/Place Comments:
Lusotitan atalaiensis Antunes and Mateus, 2003 (originally Brachiosaurus atalaiensis Lapparent and Zbyszewski, 1957) Kimmeridgian-Tithonian (LJ) of Portugal Lusotitan had been referred to Brachiosaurus. It is a long-armed taxon based on partial postcranial remains.

 

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