Episode 459: Beyond Bones: Breathing, Tendons, and Lips. New evidence of lips on T. rex, sauropod air sacs, blood vessels in Edmontosaurus, and more dinosaur soft tissues.

News:

• Air sacs were invading sauropod bones in multiple ways in the Triassic—earlier than previously thought source
• A new method to determine if scars on bones are from tendon attachments or air sac contact source
• Ossified tendons aren’t all completely ossified, some of them still have soft tissue in them source
• Soft tissue plays a very important role in how animals breathe, smell, regulate their body temperature, communicate, and more source

The dinosaur of the day: Titanosaurus

• Dubious titanosaurian sauropod that lived in the Late Cretaceous in what is now India (Lameta Formation)
• Sauropod, so walked on all fours, had a long neck and small head
• Neck was thick and tail was short
• Unclear how large Titanosaurus was (dubious, plus not many fossils found to begin with)
• Type species is Titanosaurus indicus
• Genus name means “titanic lizard”
• Named after the mythological Titans, the pre-Olympian gods in Greek mythology (12 of them)
• Described by Richard Lydekker in 1877
• First dinosaur from India to be named and officially described
• Titanosaurus named based on a partial femur (leg bone) and two incomplete tail vertebrae
• Titanosaurus named for details in the tail vertebrae
• Second species, Titanosaurus blanfordi was named in 1879 by Richard Lydekker
• Titanosaurus blanfordi was named based on a tail vertebrae found between 1860 and 1870 by William Blanford
• 14 species have been named Titanosaurus (in Argentina, Europe, Madagascar, India, and Laos, and spanning 60 million years)
• Later Titanosaurus species named based on fossils found in Argentina and Madagascar by 1896, which led to the idea that titanosaurs were Gondwanan
• Holotype vertebrae found in 1828 by Captain William Henry Sleeman of the East India Company army
• Found the fossils on Bara Simla Hill, near the Gun Carriage Factory, while looking for petrified wood
• Sleeman discovered the fossils just four years after Megalosaurus was named, in 1824, and 14 years before Owen coined the term Dinosauria, in 1842
• Sleeman wrote “I made the first discovery of fossil remains in the Nerbudda valley. I went first to a hill within sight of my house in 1828, and searched exactly between the plateau of basalt that covered it, and the stratum immediately below; and there I found several small trees with roots, trunks, and branches, all entire, and beautifully petrified. They had been only recently uncovered by the washing away of a part of the basaltic plateau. I soon after found some fossil bones of animals”
• Took over 50 years for Titanosaurus to get named
• Sleeman gave two pieces to G. G. Spilsbury, a surgeon, who also excavated a third bone, and then sent the fossils in 1832 to antique dealer James Prinsep in Calcutta, who figured out they were fossils and sent them back to Sleeman
• By 1862, Hugh Falconer, superintendent of the Geological Survey of India, had the vertebrae, and he thought it was reptilian so he took measurements and illustrated them
• Medlicott found a fragmentary leg bone (femur) in 1871 from the same area the vertebrae were found
• After Falconer died, Lydekker described them as Titanosaurus indicus
• Lydekker knew it was a dinosaur and said there were unique features in the tail vertebrae but not in the femur. He wrote “If the femur had been found alone, I should have referred it to the genus Cetiosaurus, but the vertebrae forbid this view”
• The femur and vertebrae came from the same place but not from the same layer/stratigraphic level. Because of this, in 1933 Friedrich von Huene and Charles Matley referred the femur to Antarctosaurus, a titanosaur found in Argentina
• Why were fossils found in India referred to a dinosaur genus from South America?
• At the time, the other fossils found in India couldn’t be compared with Titanosaurus indicus but they had several things in common with Antarctosaurus. Also, Lydekker had set a precedent for linking dinosaurs across Gondwana when he identified Titanosaurus species in Madagascar and South America
• And Huene thought there was a land bridge in the Cretaceous between South America and southeastern Asia
• After Huene and Matley in 1933, took more than 50 years until the next discovery of Late Cretaceous dinosaurs in India (abelisaurid and titanosaur skeletons and eggs and nest sites, found in 1981)
• In 2003 Jeffrey Wilson and Paul Upchurch re-evaluated Titanosaurus (and all 14 species)
• Titanosaurus was a wastebasket taxon for a while, for titanosaurs found in Europe, South America, and other parts of Asia
• Found Titanosaurus indicus to be invalid “because it is based on ‘obsolescent’ characters—once diagnostic features that have gained a broader taxonomic distribution over time”
• Means these features thought to be unique to Titanosaurus are found in other titanosaurs
• Found that the group Titanosauria was still valid though
• To his credit, when Lydekker named the two species of Titanosaurus, only 115 dinosaur species had been named
• Since Titanosaurus, lots of titanosaurs and non-titanosaurs have been found with the same features in the tail vertebrae as Titanosaurus (includes diplodocoids and Mamenchisaurus)
• Some of those features are unique to Titanosauria and others found in other sauropod lineages
• Former species include rahioliensis (based on teeth, now thought to be an indeterminate neosauropod), colberti (now Isisaurus), australis (now Neuquensaurus), nanus (another nomen dubium), robustus (now Neuquensaurus), madagascariensis, falloti (too fragmentary to know), valdensis (now a nomen dubium) lydekkeri (unclear), and dacus (now Magyarosaurus)
• Wilson and Upchurch wrote that “History has stripped Titanosaurus of its uniqueness through obsolescence of the characters originally used to define it”
• Charles Matley collected more sauropod bones between 1917 and 1919, in the same area where Titanosaurus indicus fossils were found but in a different layer. They were found “washed about and somewhat damaged and broken before fossilization”
• Also found fragmentary bones in 1920 in the type locality of Titanosaurus blanfordi
• Fossils were assigned to Titanosaurus indicus, Titanosaurus blanfordi, ?Antarctosaurus sp., Laplatasaurus madagascariensis, and an indeterminate sauropod
• Four braincases once attributed to Titanosaurus indicus were found in different localities in India, and one was from Bara Simla (where the first Titanosaurus fossils were found), supposedly found with some skeletal fossils but those were not mapped or described
• Enough differences in the braincases that there were probably two sauropod taxa, and they were informally referred to “Antarctosaurus” and “Titanosaurus” morphs
• Unfortunately, no detailed field records and fossils from Bara Simla are not well preserved, which means the fossils found there are confusing and controversial when it comes to which dinosaurs they belong to
• In 1997, Jain and Bandyopadhyay said “Antarctosaurus” septentrionalis was a junior synonym of Titanosaurus indicus because there weren’t any big differences between the two
• However, Wilson and Upchurch said that because the fossils came from Bara Simla, which “is a poor sample from which to determine variation”, and that naming all fossils found at Bara Simla as one species will “not only create a potentially unnatural assemblage, it also forces future discoveries of presently unknown elements to be referred to it”
• Wilson and Upchurch also found that Titanosaurus blanfordi was not valid, because the features on its tail vertebrae that Lydekker described are features that may vary among sauropods (individual variation) and can’t be a diagnostic feature
• Titanosaurus rahioliensis was named based on teeth, which was not enough
• Fossils found in Madagascar, including the first record of dermal armor in a sauropod, were referred to Titanosaurus madagascariensis
• The dermal armor is not part of the holotype
• Found Titanosaurus madagascariensis to be nomen dubium, until it’s further studied (fossils include tail vertebrae, part of an arm and the dermal ossification, though Dep’eret when he described the fossils in 1896 wrote “I refer to the same animal, but without absolute certainty, a large dermal ossification”, though the fossils were found in different localities). Earlier study had found it to be Laplatasaurus, but Wilson and Upchurch said comparisons are limited
• Titanosaurus lydekkeri only known from a tail vertebra, and only know it belongs to a titanosaur
• Laplatasaurus was different from Titanosaurus because it was larger with more slender proportions
• Titanosaurus colberti was named based on a partial skeleton including part of the pelvis and forelimb
• Found Titanosaurus colberti to be a valid species but gave it a new name: Isisaurus
• Wilson and Upchurch found that of the 14 Titanosaurus species, only 5 were valid, and four of them were renamed (Neuquensaurus, Magyarosaurus, Laplatasaurus, and Isisaurus). But, they also mentioned “Titanosaurus” sp.
• Even though the paper said Titanosaurus is a nomen dubium, they still consider one species, sort of (sp. means not identified on the species level or not related to other known species)
• Also the original Titanosaurus indicus and blanfordi fossils went missing for many years
• Unclear when exactly they went missing
• But Dhananjay Mohabey found the fossils were only lost because there was no good inventory of the collections, so he started a study to find them, and in 2012, he and Subhasis Sengupta found the holotype vertebra of Titanosaurus indicus (in a batch of fossils Lydekker left behind in 1878, which is why it didn’t have an official inventory number), and also found the vertebrae of Titanosaurus blanfordi
• Titanosaurs were very diverse and found all over the world, on all seven continents
• They lived until the end of the Cretaceous
• Group includes some of the largest land animals, like Patagotitan (estimated to be 121 ft or 37 m long and weigh 76 tons)
• Not all were large, like Magyarosaurus that weighed about 1 ton
• Titanosaurs had wide chests, and the “wide-legged” stance, and stocky forelimbs that were often longer than the hind limbs
• Not many titanosaur skulls found, based on ones found, skulls were small
• Some titanosaurs, like Saltasaurus, had osteoderms
• Titanosaur eggs have been found, which include embryos and preserve skin (soft tissues!)
• Earlier this year, in 2023, a bunch of titanosaur eggs were found in India (talked about in episode 430)
• From about 70 million years ago
• Nests packed tightly together, so likely the titanosaurs didn’t stick around to take care of their young (if they had, may have trampled the nests)
• A 2015 study found embryonic skin from titanosaur eggs found in Patagonia, Argentina, and found scale patterns that were similar to the patterns of osteoderms on Saltasaurus
• Also to connect to the soft tissues in this episode, titanosaurs had air sacs
• Tito Aureliano and others published a study in 2021 (talked about in episode 386) about air sacs in a saltasaurid titanosaur that lived in the Late Cretaceous in what is now Brazil (had the pneumosteal bone)
• Titanosaurus the dinosaur is not to be confused with the kaiju Titanosaurus (Japanese term and a subgenre of science fiction about giant monsters—like Godzilla)
• The kaiju Titanosaurus appeared in the 1975 film Terror of Mechagodzilla
• In the movie, a mad scientist Shinzo Mafune discovers the Titanosaurus and says he can control its mind (people think he’s insane and he loses all credibility)
• He does control the Titanosaurus and gets his revenge (before he controls the Titanosaurus, Titanosaurus was peaceful)
• In the movie, Titanosaurus is 196 ft (60 m) tall and weighs over 30,000 tons
• Designed to look like a spinosaur (and is aquatic), and has a crocodile-like snout, a sail-like fin, and roars
• Also stands on two legs and tail drags
• But does have a long neck
• Colors are red, yellow, and black, with a beige belly
• Can use its tail as a fan to create winds strong enough to destroy buildings, or create whirlpools in water
• Good swimmer and can walk on land too
• (spoilers) Gets defeated by Godzilla

Fun Fact:

T. rex likely covered its teeth in large lips and it probably didn’t have the muscles to bare its teeth.

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