Initial artwork from scientific illustrator Emiliano Troco illustrating a Brontosaurus (likely the most popular sauropod dinosaur) serving as a community engineer in a vegetated and warm landscape not different to modern-day savannah type biomes. The animal is indulging in a semi-arid open landscape where temperature conditions might have favoured their ecology: as hypothesized in our paper, sauropods may have been an exception in Dinosauria for being exclusively capable of occupying warmer, lower latitude environments, where may have been more effective, possibly hinting to a more heterotherm-inclined thermophysiology than other dinosaur groups, i.e. theropods and ornithischians. Credit: Emiliano Troco
Giant, long-necked sauropods, believed to include the biggest land animals ever to have existed, preferred to reside in warmer, more tropical regions in the world, suggesting they may have had a various physiology from other dinosaurs, according to a brand-new research study.
Giant, long-necked sauropods, believed to consist of the largest land animals ever to have existed, chosen to reside in warmer, more tropical areas on Earth, recommending they might have had a different physiology from other dinosaurs, according to a new study led by researchers at UCL and the University of Vigo.
The research study, released in the journal Current Biology, examined the enigma of why sauropod fossils are only found at lower latitudes, while fossils of other primary dinosaur types seem ubiquitously present, with numerous located in the polar regions.
The scientists examined the fossil record across the Mesozoic period (the time of the dinosaurs), lasting from around 230 to 66 million years ago, looking at incidents of fossils of the three main dinosaur types: sauropods, that include the Brontosaurus and the Diplodocus, theropods (” lizard-hipped”), that include velociraptors and Tyrannosaurus rex, and ornithischians (” bird-hipped”) such as the Triceratops.
Integrating this fossil data with information about environment throughout the period, together with details about how continents have actually moved across the world, the researchers concluded that sauropods were restricted to warmer, drier environments than other dinosaurs. These environments were most likely to be open, semi-arid landscapes, similar to todays savannahs.
Graphical abstract revealing the latitudinally more restricted circulation of sauropod dinosaurs (white) compared to other dinosaurs (in black) Credit: Current Biology
Co-author Dr. Philip Mannion (UCL Earth Sciences) said: “Our research study shows that some parts of the planet constantly appeared to be too cold for sauropods. They appear to have prevented any temperatures approaching freezing. Other dinosaur types, on the other hand, might thrive in Earths polar regions, from innermost Antarctica to polar Alaska– which, due to the warmer climate, were ice-free, with lush greenery.
” This recommends sauropods had different thermal requirements from other dinosaurs, relying more on their external environment to warm their bodies– somewhat closer to being cold-blooded, like modern-day reptiles. Their grand size hints that this physiology may have been unique.”
Very first author Dr. Alfio Alessandro Chiarenza, previously of UCL who is now based at the University of Vigo, Spain, said: “It might be that sauropods were physiologically incapable of flourishing in colder areas, or that they thrived less well in these locations than their dinosaurian cousins and were outcompeted.
” A mix of features may have helped sauropods shed heat more quickly than mammals do today. Their long necks and tails would have offered them a bigger surface location, and they might have had a breathing system more similar to birds, which is much more efficient.
” Some types of ornithischians and theropods are understood to have actually had plumes or downy fur assisting them retain body warmth. This recommends they may have created their own temperature. For sauropods, nevertheless, there is no evidence of this sort of insulation.
” Sauropods techniques for keeping their eggs warm might also have actually varied from the other dinosaurs. Theropods probably warmed eggs by sitting on them, whereas ornithischians seem to have used heat generated by decomposing plants. Sauropods, on the other hand, might have buried their eggs, depending on heat from the sun and the ground.”
In their paper, the scientists noted that the fossil record showed no events of sauropods above a latitude of 50 degrees north– an area encompassing most of Canada, Russia, northern Europe, and the UK– or listed below 65 degrees south, including Antarctica. In contrast, there are abundant records for ornithischians and theropods living above 50 degrees north in later durations (from 145 million years ago).
To evaluate if this was a real reflection of where sauropods lived, scientists utilized an analytical method to change for spaces in the fossil record, and also analyzed where the greatest diversities of dinosaur types were in different durations throughout the Mesozoic era.
They combined fossil information with climate data, permitting a price quote of the temperature series of the dinosaur types habitats, discovering that sauropods range across the latitudes was more limited during chillier durations.
They then used environment modeling to infer which regions of the world would likely be suitable for sauropods and the other dinosaur types to live.
While in the past it was believed that dinosaurs were ectothermic (” cold-blooded”), like reptiles today, depending on the external environment to heat their bodies, it is now thought they were closer to “warm-blooded” mammals, producing some of their own temperature (endothermic).
The research study authors said sauropods might have had a distinct in-between physiology, closer to being cold-blooded than other dinosaur types.
Referral: “Climatic constraints on the biogeographic history of Mesozoic dinosaurs” by Alfio Alessandro Chiarenza, Philip D. Mannion, Alex Farnsworth, Matthew T. Carrano and Sara Varela, 17 December 2021, Current Biology.DOI: 10.1016/ j.cub.2021.11.061.
The study included researchers from UCL, the University of Vigo, the University of Bristol, and the Natural Museum of Natural History, Smithsonian Institution, Washington, USA, and received financing from the European Research Council and the Royal Society.
Original art work from clinical illustrator Emiliano Troco illustrating a Brontosaurus (likely the most well-known sauropod dinosaur) acting as a community engineer in a vegetated and warm landscape not dissimilar to modern-day savannah type biomes. The animal is basking in a semi-arid open landscape where temperature level conditions may have favoured their ecology: as hypothesized in our paper, sauropods may have been an exception in Dinosauria for being solely capable of living in warmer, lower latitude environments, where might have been more effective, maybe hinting to a more heterotherm-inclined thermophysiology than other dinosaur groups, i.e. theropods and ornithischians. Co-author Dr. Philip Mannion (UCL Earth Sciences) said: “Our research study shows that some parts of the world constantly seemed to be too cold for sauropods.” Sauropods techniques for keeping their eggs warm might likewise have differed from the other dinosaurs. Sauropods, on the other hand, might have buried their eggs, relying on heat from the ground and the sun.”
