Name: Barosaurus ‭(‬heavy lizard‭)‬.
Phonetic: ‭B‬ar-roe-sore-us.
Named By: Othniel Charles Marsh‭ ‬-‭ ‬1890.
Synonyms: Barosaurus affinis.
Classification: Chordata,‭ ‬Reptilia,‭ ‬Dinosauria,‭ ‬Saurischia,‭ ‬Sauropodomorpha,‭ ‬Sauropoda,‭ ‬Diplodocidae,‭ ‬Diplodocinae.
Species: B.‭ ‬lentus‭ (‬type‭)‬.
Diet: Herbivore.
Size: Up to about‭ ‬27.5‭ ‬meters long‭ (‬based upon ROM‭ ‬3670‭).
Known locations: USA,‭ ‬including the states of‭ ‬Colorado,‭ ‬Oklahoma,‭ ‬South Dakota,‭ ‬Utah and Wyoming‭ ‬-‭ ‬Morrison Formation.
Time period: Late Kimmeridgian of the Jurassic.
Fossil representation: Partial post cranial remains of several individuals.

       The modern history of the sauropod dinosaur Barosaurus begins in‭ ‬1889‭ ‬with the discovery of the first Barosaurus fossils by a Ms E.‭ ‬R.‭ ‬Ellerman in South Dakota.‭ ‬Six caudal‭ (‬tail‭) ‬vertebrae were subsequently recovered by the famous American palaeontologist Othniel Charles Marsh later that year,‭ ‬though other remains were left at the site until such time that they could be safely recovered and transported.‭ ‬In‭ ‬1898‭ ‬one of Marsh’s assistants,‭ ‬George Weiland recovered these remains which included limbs,‭ ‬ribs and more vertebrae,‭ ‬and allowed for the identification of Barosaurus as a diplodocid sauropod.‭ ‬Later,‭ ‬fossils of Barosaurus were the last to ever be described by Charles Othniel Marsh before his death in‭ ‬1899.‭ ‬These were two metatarsals assigned to a new species,‭ ‬B.‭ ‬affinis,‭ ‬though today this species is treated as a synonym to the type species,‭ ‬B.‭ ‬lentus.
       Today Barosaurus is known by the remains of several individuals that have all been recovered from the Kimmeridgian aged deposits of the famous Morrison Formation.‭ ‬As already mentioned,‭ ‬Barosaurus is a diplodocid sauropod,‭ ‬which means that it was of the kind that were very long with slender necks and tails that were whip-like on the end.‭ ‬It should be mentioned at this point that the end of the tail of Barosaurus is still unknown at the time of writing,‭ ‬but it would be highly unusual for a diplodocid to not have a whip-like tail.‭ ‬Barosaurus can be further classified as a diplodocine diplodocid rather than an apatosaurine diplodosaurid.‭ ‬Diplodocines are classed under the Diplodocinae and they are different to the apatosaurines‭ (‬classed under the Apatosaurinae‭) ‬in that they are more gracile‭ (‬lightly built‭) ‬than their heavier cousins.
       The main features that make Barosaurus unique to other diplodocids are in the vertebrae,‭ ‬and usually Barosaurus is compared to the famous Diplodocus and Apatosaurus‭ .‭ ‬Both Diplodocus and Apatosaurus have fifteen cervical‭ (‬neck‭) ‬and ten dorsal‭ (‬back‭) ‬vertebrae.‭ ‬Barosaurus is known to have had fifteen cervical vertebrae but only nine‭ ‬dorsal‭ ‬vertebrae.‭ ‬Where the tenth dorsal vertebra went to is unknown,‭ ‬but it’s possible that it may have over time adapted to become a sixteenth cervical vertebrae.‭ ‬The cervical vertebrae‭ ‬of Barosaurus‭ ‬were also up to one and a half times longer than the cervical vertebrae of Diplodocus meaning that Barosaurus would have proportionately longer neck than Diplodocus.‭ ‬The caudal‭ (‬tail‭) ‬vertebrae of Barosaurus however were proportionately shorter than those of Diplodocus,‭ ‬meaning that the overall length of the tail would have been shorter in Barosaurus.‭ ‬The neural spines of the vertebrae in Barosaurus are also shorter and less complex than those of Diplodocus.
       Much of the post cranial skeleton of Barosaurus is known,‭ ‬though there are two glaring omissions‭; ‬the feet and the head.‭ ‬Barosaurus is actually not an exception,‭ ‬the feet and skulls are the two most commonly missing parts when sauropod remains are found.‭ ‬This is because they are fairly small and jointed and therefore can become easily detached from the rest of the skeleton before preservation.‭ ‬As a diplodocid,‭ ‬Barosaurus would be expected to have had a skull similar to relative genera,‭ ‬elongated with a sloping snout,‭ ‬housing peg-like teeth for stripping vegetation from branches.
       Aside from being similar to Diplodocus and Apatosaurus,‭ ‬Barosaurus also seems to have shared the same habitats as them as well.‭ ‬Another sauropod named Haplocanthosaurus‭ ‬may have also come into contact with Barosaurus.‭ ‬In addition to these,‭ ‬macronarian sauropods such as Camarasaurus and Brachiosaurus would have also been present on the same landscapes as Barosaurus.‭ ‬There would have course been other dinosaurs such as herbivores like Stegosaurus,‭ ‬Camptosaurus and Mymoorapelta,‭ ‬and predators such as Ornitholestes,‭ ‬Torvosaurus,‭ ‬Saurophaganax and Allosaurus.‭ ‬Barosaurus may have fallen prey to some of these larger predators,‭ ‬though the smaller juveniles would have been at more of a risk than fully grown adults.
       For a time Barosaurus was once thought to have lived in Africa as well as North America.‭ ‬This all comes down to a‭ ‬1907‭ ‬discovery of two sauropod skeletons by a German palaeontologist named Eberhard Fraas,‭ ‬who at the time thought that he was creating a new genus of sauropod named Gigantosaurus.‭ ‬However,‭ ‬the name Gigantosaurus had already been named for a more obscure set of sauropod remains from England,‭ ‬so a new genus was erected for them by Richard Sternfeld and named Tornieria in 1911.‭ ‬Fossils of Tornieria africana however were re-assigned by another German palaeontologist named Werner Janensch to Barosaurus.‭ ‬Since this however,‭ ‬other palaeontologists have questioned the reasoning of such a move.‭ ‬One species formerly known as T.‭ ‬robustus was re-examined in‭ ‬1991‭ ‬and revealed to be a titanosaurs and added to its own new genus Janenschia.‭ ‬Other material once assigned as T.‭ ‬africanus was confirmed to be different to known North American diplodocids in‭ ‬2006,‭ ‬which saw a subsequent resurrection of the Tornieria genus.‭ ‬This also rather obviously means that Barosaurus remains known only from North American deposits.

       ROM‭ ‬3670
       One of the most exciting discoveries,‭ ‬or rather rediscoveries concerning Barosaurus happened in‭ ‬2007.‭ ‬Palaeontologist and curator of the Royal Ontario Museum David Evans spotted a reference to a Barosaurus skeleton that had been traded with the Carnegie Museum and sent to the Royal Ontario Museum in‭ ‬1962.‭ ‬Strangely,‭ ‬these fossils don’t seem to have made it out of storage upon arriving and just disappeared from everyone’s memory.‭ ‬Realising that there might be a scientifically valuable specimen somewhere in the museum,‭ ‬Evans searched the storage bays and began finding the fossils of the missing Barosaurus.
       This Barosaurus specimen is known as ROM‭ ‬3670,‭ ‬though those who visit and work with it know it better as‭ ‘‬Gordo‭’‬.‭ ‬With the rediscovery plans were immediately put into motion to set up a new display,‭ ‬though in order to get the display ready,‭ ‬not all of the fossil casts could be mounted in time.‭ ‬In fact more bones of Barosaurus were still in storage several years after this mounting was completed which means that it may be re-mounted but more completely in the future.‭ ‬Unfortunately the skull is still not known,‭ ‬so the one that appears upon the display is that of a Diplodocus,‭ ‬which should at the very least be a fairly close match.
       ROM‭ ‬3670‭ ‬is valuable for two reasons.‭ ‬With more fossils of this dinosaur coming out of storage,‭ ‬it may actually be the most complete Barosaurus skeleton so far recovered.‭ ‬This skeleton also seems to have come from an individual which seems to have grown up to twenty-seven and a half meters long,‭ ‬making it the largest individual Barosaurus known.

Further reading
-‭ ‬Description of new dinosaurian reptiles‭ ‬-‭ ‬Othniel Charles Marsh‭ ‬-‭ ‬1890.
-‭ ‬The sauropod dinosaur Barosaurus Marsh:‭ ‬redescription of the type specimens in the Peabody Museum,‭ ‬Yale University‭ ‬-‭ ‬Richard S,‭ ‬Lull‭ ‬-‭ ‬1919.
-‭ ‬Sauropod dinosaurs of the Morrison Formation‭ (‬Upper Jurassic‭)‬,‭ ‬Black Hills,‭ ‬South Dakota and Wyoming‭ ‬-‭ ‬John R.‭ ‬Foster‭ ‬-‭ ‬1996.
-‭ ‬A phylogenetic analysis of Diplodocoidea‭ (‬Saurischia:‭ ‬Sauropoda‭) ‬J.‭ ‬A.‭ ‬Whitlock‭ ‬-‭ ‬2011.
- The neck of Barosaurus was not only longer but also wider than those of Diplodocus and other diplodocines. - PeerJ Preprints. 1: e67v1. - Michael P. taylor & Mathew J. Wedel - 2013.


Random favourites