Titanosaurs (members of the group Titanosauria) is a diverse group of extinct sauropoddinosaurs which included Saltasaurus and Isisaurus. The titanosaurs were the last surviving group of long-necked sauropods, with taxa still thriving at the time of the extinction event at the end of the Cretaceous.
The group includes the largest land animals known to have existed, such as Patagotitan ~ estimated at 37 m (121 ft) long with a weight of 69 tonnes (76 tons)[1][2][3] and the comparably sized Argentinosaurus and Puertasaurus from the same region. The group's name comes from the type genus (now potentiqlly considered a nomen dubium)Titanosaurus.[4] Together with the brachiosaurids and relatives, titanosaurs make up the larger clade Titanosauriformes.[5]
An unidentified Titanosaurid in comparission to a Human
A unique group of gigantic sauropod dinosaurs quite literally called: the Titanosauria, or "titanic reptiles." Instead of going extinct like many other sauropod species throughout their ecosystems and time periods; titanosaurs flourished long after their more famous cousins vanished.[6][7][8][9]
Another unidentified Titanosaurid
There were nearly 100 species of titanosaurs, making up more than 30% of known sauropod dinosaurs. They varied greatly in size. From the largest known sauropods ever discovered, including Argentinosaurus, Patagotitan and Futalognkosaurus, whose weight exceeded 60 tons (54.4 metric tons) and were bigger than a semitruck, to the smallest known sauropods, including Rinconsaurus, Saltasaurus and Magyarosaurus, which were around only 6 tons (5.4 metric tons) and about the size of an African elephant.[10][11]
A herd of Traveling Titanosaurids
Not only were they large and in charge on all seven continents, they held their own amid the newly evolved duck-billed and horned dinosaurs, until an infamous asteroid deeply struck Earth and ended the age of non-avian dinosaurs permanently.
The key secret to titanosaurs' remarkable biological success may be how they merged the best of both reptile and mammal characteristics to form a unique way of life![12][13][14]
A swimming - traversing Titanosaurid. Credit: olorotitan
Had it not been for the asteroid impact 66 million years ago, these long-lived, incredibly diverse and wildly successful animals probably would have kept on thriving, in places as distant as Madagascar, Romania, North America and even Antarctica. Instead, titanosaurs were among the witnesses to—and victims of—the most recent mass extinction on Earth.[15]
Geography, Spread and Diversification[]
Titanosaurs originated by the Early Cretaceous Period, nearly 126 million years ago, at a time when many of the Earth's landmasses were much closer together than they are today.
Over the next 75 million to 80 million years, the continents slowly separated, and titanosaurs drifted along with the changing formations, becoming distributed worldwide![16]
Reproduction[]
A herd of Brazilian Titanosaurids traveling
Similiar to many known reptile species; the titanosaurs began life more comparatively tiny hatchings; literally from the eggs no bigger than grapefruits.[17]
The best data on titanosaur nests and eggs comes from a site in Argentina called Auca Mahuevo, featuring 75 million-year-old exposed rocks. The site contains hundreds of fossilized nests containing thousands of eggs, some of which are so well preserved, scientists recovered skin impressions from ancient embryos![18]
The sheer immense number of innumerable nests found directly together, in multiple geological layers, suggests titanosaurs returned to this site repeatedly to lay their eggs. Very similar to some speciesnof modern reptiles as well as modern avians.[19][20]
Titanosaurus Eggs fossils
The nests are too closely spaced, it's quite unlikely an adult titanosaur would have been able to move actually freely through the nesting ground. The Titanosaurs likely; presumably; theorized to had a much more '' hands-off '' parenting style.[21]
This is very similar to many reptiles that lay numerous eggs and don't spend much time tending the nest or taking care of hatchlings. Such as Turtles; even modern Giant Turtles; Iguanas; Some species of snakes as well as all known Varanids.
A titanosaur hatchling would have been roughly 1 foot (30 centimeters) tall, 3 feet (1 meter) long and 5–10 pounds (2.5–5 kg). Recent evidence from a site in Madagascar suggests these tiny titans were born ready to rumble; meaning that they were either fully precocial or even perhaps Superprecocial similar to some modern avian and reptile species.[22]
A titanosaur from Madagascar called Rapetosaurus krausei is known from fossils of tiny hatchlings, giant adults and a variety of in-between sizes. Credit: Jordan Mae Harris
Fossilized bones from the species Rapetosaurus suggest that by the time they would have been just knee high to a modern human, they were presumably; quite likely able to be fending for themselves. Microscopic details recorded deep within the bones indicate baby Rapetosaurus likely foraged quite independently for different types of plants and moved much more nimbly especially compared their lumbering gargantuan adult relatives.
Growth[]
Bone data actually shows titanosaur growth rates were on par with mammals like whales! Much, much faster than any known living reptile! This meaning they would have reached their enormous adult sizes in just a few decades. Scientists can't know for sure how long titanosaurs lived, but based on largest land animals living today, titanosaurs lived possibly 60 or more years![23][24][25]
An unidentified Titanosaurid in comparission to a Human
The Titanosaurs' bones at high magnification to better understand their growth. Scientists look at the microscopic patterns of bone minerals as well as the density and architecture of the spaces that held blood vessels and cells.[26][27]
The more dense the blood supply is to a bone, the faster that animal grows. These signatures are also present in living animals and can accurately reflect growth rates, anomalies and even age.[28]
The rapid growth rates of sauropods was partly due to their body temperatures. By studying the chemistry of fossilized teeth and eggshells, scientists have determined titanosaurs had body temperatures ranging from about 95°F to 100.5°F (35°C to 38°C). That's higher than that of crocodiles and alligators, about the same as modern mammals and a bit lower than most birds, whose bodies can regularly get as warm as 104°F (40°C).[29]
A Titanosaurid Skull
Titanosaurs' rapid growth rates were also powered by their prodigious appetites for plants. Microscopic patterns of scratches, wear and pits on their teeth indicate titanosaurs in Argentina fed on a diverse diet rich in grit, suggesting they were dining on plants found lower to the ground, where sediment would be more commonly found.[30]
In India, chunks of fossilized feces, otherwise known as coprolites, show titanosaurs there ingested everything from ground-level plants all the way up to the leaves and branches of trees.[31][32]
Like all dinosaurs, titanosaurs replaced their teeth throughout life. But data shows they replaced each tooth about every 20 days for maximum efficiency, one of the highest tooth-replacement rates known for dinosaurs.[33]
