#sauropodomorphs

[fishsfailureson]

A lone Saturnalia rests in its favourite spot as the sun sets

[saritapaleo]

Archovember 2024 Day 23 - Ledumahadi mafube

With a name meaning “giant thunderclap at dawn” in Sesotho, Ledumahadi mafube is one of the first sauropodomorphs known to become a quadrupedal giant. Living in Early Jurassic South Africa, it is known from fragmentary remains, but we can infer its appearance based on its relatives, though it was significantly larger than them. Ledumahadi is estimated to have weighed around 12 tonnes (13 short tons), similar in body mass to Diplodocus, though its neck and tail were likely shorter. At a time when most dinosaurs were small, scampering things, Ledumahadi would have been the largest animal around, and it hinted at what would someday be in store for this clade of giants.

Ledumahadi lived in the Elliot Formation, which would have been a semi-arid landscape with meandering rivers. The most common dinosaur here was the smaller, bipedal sauropodomorph Massospondylus. Other sauropodomorphs Ledumahadi would have lived alongside include Blikanasaurus, Aardonyx, Antetonitrus, and Pulanesaura. It would have also come across the basal ornithischians Heterodontosaurus, Abrictosaurus, Lycorhinus, and Lesothosaurus. Small pseudosuchians like Sphenosuchus, Litargosuchus, and Orthosuchus would have prowled through the underbrush or swam through the rivers. Ledumahadi, or at least its young, could have been preyed on by the neotheropod Dracovenator.

This art may be used for educational purposes, with credit, but please contact me first for permission before using my art. I would like to know where and how it is being used. If you don’t have something to add that was not already addressed in this caption, please do not repost this art. Thank you!

[misterrogers22]

The latest episode of Dinosaurs Lately is out for Christmas ! Episode 7 - Sauropodomorphs (Winter 2025) is available for download or streaming at Podbean: https://jurassickparkcast.podbean.com/e/dinosaurs-lately-sauropodomorphs-winter-2025/ and Youtube: https://www.youtube.com/watch?v=C6pZZc9OT0s

Lísie V S Damke et al. (2024). “New specimens of Saturnalia tupiniquim (Dinosauria: Sauropodomorpha): insights into intraspecific variation, rostral anatomy, and skull size.” Zoological Journal of the Linnean Society doi: https://doi.org/10.1093/zoolinnean/zlae156

#Saturnalia

David M Lovelace et al. (2025). "Rethinking dinosaur origins: oldest known equatorial dinosaur-bearing assemblage (mid-late Carnian Popo Agie FM, Wyoming, USA)," Zoological Journal of the Linnean Society https://doi.org/10.1093/zoolinnean/zlae153

#Ahvaytum #bahndooiveche

Hechenleitner, E.M., et al. (2025) A long-necked early dinosaur from a newly discovered Upper Triassic basin in the Andes. Nature https://doi.org/10.1038/s41586-025-09634-3

#Huayracursor #jaguensis

Samantha L. Beeston, et al. (2025). “New information on Late Triassic sauropodomorph dinosaurs provides support for the independent acquisition of postcranial skeletal pneumaticity in avemetatarsalian lineages.” Journal of Anatomy https://onlinelibrary.wiley.com/doi/10.1111/joa.70045

#sauropodomorph

Claire Peyre de Fabrègues,et al. (2025). “Leyesaurus marayensis (Dinosauria, Sauropodomorpha) from Northwestern Argentina: an update.” Ameghiniana https://www.ameghiniana.org.ar/index.php/ameghiniana/libraryFiles/downloadPublic/127

#leyesaurus #marayensis

Thomas Filek et al. (2025). “Tail of defence: an almost complete tail skeleton of Plateosaurus reveals possible defence strategies.” Royal Society Open Science https://royalsocietypublishing.org/doi/10.1098/rsos.250325

#plateosaurus #trossingensis

Sina F. J. Dupuis, et al. (2025). “Osteology and histology of a Plateosaurus trossingensis from the Upper Triassic of Switzerland with an advanced chronic pathology.” Swiss Journal of Palaeontology https://link.springer.com/article/10.1186/s13358-025-00368-3 #plateosaurus #trossingensis

Michael W. Maisch et al. (2024). Neubewertung von "Plateosaurus" ornatus von Huene, 1908 - ein früher Ornithischier aus dem Rhätbonebed? [Annual Report of the Society for Natural History in Württemberg] #plateosaurus #ornatus

Rémi Lefebvre et al. (2025). Evolution of the sauropodomorph astragalus: relationships with the emergence of the sauropod bauplan and weight-bearing function, and critical appraisal of evolutionary rate estimation. Zoological Journal of the Linnean Society https://academic.oup.com/zoolinnean/article-abstract/204/4/zlaf077/8224426

André O Fonseca et al. (2025). “Osteology of the appendicular skeleton of #Macrocollum #itaquii sheds light on early dinosaur wrist evolution.” Zoological Journal of the Linnean Society https://academic.oup.com/zoolinnean/article-abstract/205/1/zlaf100/8248636

Alessandro Lania et al. (2025) Craniomandibular osteology of a new massopodan sauropodomorph from the Late Triassic (latest Norian) of Canton Aargau, Switzerland Swiss Journal of Palaeontology https://link.springer.com/article/10.1186/s13358-025-00373-6

Xiang-Yuan Chen, et al. (2025). “A new species of Xingxiulong from the Lower Jurassic Lufeng formation of Yunnan Province, China.” Historical Biology https://www.tandfonline.com/doi/full/10.1080/08912963.2025.2458130 #Xingxiulong #yueorum

Ya-Ming Wang, et al. (2025). “A new Early Jurassic dinosaur represents the earliest-diverging and oldest sauropodomorph of East Asia.” Scientific Reports https://www.nature.com/articles/s41598-025-12185-2 #wudingloon #wui

Paul M Barrett et al. (2024). “A brief history of #Massospondylus: its discovery, historical taxonomy and redescription of the original syntype series.” Palaeontologia africanahttps://wiredspace.wits.ac.za/items/ac85b6f0-23a8-4fa7-a1a2-878f3ee610ff #carinatus

Ethan D. Mooney, et al. (2025) Massospondylus embryos and hatchling provide new insights into early sauropodomorph ontogeny Swiss Journal of Palaeontology https://link.springer.com/article/10.1186/s13358-025-00382-5

Han, F., et al. (2023). Exceptional Early Jurassic fossils with leathery eggs shed light on dinosaur reproductive biology. National Science Review doi: 10.1093/nsr/nwad258 #Qianlong #shouhu

Qian-Nan Zhang, et al. (2024). “The largest sauropodomorph skull from the Lower Jurassic Lufeng Formation of China.” PeerJ https://peerj.com/articles/18629/

#Lishulong #wangi

[saritawolff]

Patreon request for rome.and.stuff (Instagram) Plateosaurus trossingensis! (that I went a liiiittle overboard with the markings on)

Plateosaurus trossingensis is the type species of the Plateosaurids, a family of early Sauropodomorphs that existed long before the titanic long-necked sauropods of the Jurassic and Cretaceous. The Plateosaurids represented a time of transitioning for Sauropodomorphs, going from small bipeds scampering through the underbrush to lumbering giants with necks built to reach up to the tastiest leaves. However, Plateosaurus could not pronate its hands, making it incapable of walking quadrupedally. Discovered in 1834, it was the fifth named non-avian dinosaur genus still considered valid today, and is now one of the best known to science, with over 100 individuals found!

Unusual for dinosaurs, Plateosaurus trossingensis didn’t seem to have a constant max adult size. Individuals would grow rapidly and continue growing after sexual maturity, slowing down over time. Their growth was determinate, meaning they would eventually stop growing at a point, however, this point seemed to vary wildly between individuals. Adult specimens have ranged between 4.8 and 10 metres (16 and 33 ft) long and weighed between 600 and 4,000 kilograms (1,300 and 8,800 lb). While I have depicted a fairly average individual here, others have been found more than twice its size!

(Size chart by Slate Weasel)

Plateosaurus trossingensis lived in the Late Triassic of Central Europe. Unfortunately though, while P. trossingensis was apparently quite common in the Trossingen Formation, very little contemporary dinosaurs have been found there. Partial remains from other prosauropods include that of Tuebingosaurus, Gresslyosaurus, Ruehleia, and the lighter bodied Plateosaurus longiceps. Indeterminate coelophysoid remains also exist, but the most complete carnivore found here is Liliensternus, which could have preyed on smaller Plateosauruses. Other animals from this formation include turtles and temnospondyl amphibians, so this was a moist environment. It is suggested that the reason we tend to find more Plateosauruses here than other species is that their size and weight would have caused them to get mired in mud more easily, as opposed to the smaller species in the formation.

(Btw, the request tier for Patreon starts at only $5 a month. Link is pinned at the top of my page!)

[a-dinosaur-a-day]

honestly Sauropoda should've been defined as everything closer to Cetiosaurus than Megalosaurus or Iguanodon, that way we wouldn't have to use the accurate but cumbersome "non-sauropod sauropodomorphs", or the paraphyletic "prosauropods" to refer to sauropod relatives from before the arbitrary cutoff point, we could just call them all sauropods

yeaaaaaaaaaah taxonomy is a field riddled with major mistakes

[fundinofactoftheday]

Dinofact #58

Mussaurus, a sauopodomorph, meaning "mouse lizard", was so named because originally, the only known specimens were very small, leading scientists to believe that the dinosaur was an incredibly small sauropodomorph. However, these specimens have since been confirmed to be infant and juvenile, and adult specimens have been discovered. Current estimates show that the dinosaur may have been 6 meters (20 feet) long and weighed more than 1,000 kilograms (2,200 pounds), so the name may be a bit of a misnomer.

[sciencenewsforstudents]

There’s more than one way to build a giant dinosaur

Some early long-necked dinosaurs may have built big bodies from a different blueprint than their later giant relatives.

Long-necked sauropods (SAHR-oh-pahdz) are the largest animals known to have walked on Earth. These giant plant-eating dinos include Apatosaurus and Brontosaurus. Their early relatives were big, too. Some, though, may have used a different strategy to get their girth, shows a new study.

Most early sauropod relatives shared a common suite of features. They had sturdy, pillarlike legs. They had elongated necks and forelimbs. And their bones grew continuously rather than in seasonal spurts. Scientists had considered this an essential blueprint for massive plant-eaters. But at least some ancient giants may have used a different strategy to get so big. That’s the conclusion of a new fossil analysis of sauropodomorphs (SAHR-oh-PAHD-oh-morfz). That group includes sauropods and some of their similarly shaped relatives.

Explainer: How a fossil forms

Cecilia Apaldetti is a paleontologist. She works at the Universidad Nacional de San Juan in Argentina. She and her colleagues examined fossils of four early sauropodomorphs. One belonged to a newly identified species. The team named it Ingentia prima (Ihn-GEHN-tee-uh PREE-muh). The other three were an already known sauropodomorph called Lessemsaurus sauropoides (Lehs-ehm-SAHR-us sahr-uh-POY-deez). These “Lessemsauridae” (Lehs-ehm-SAHR-ih-day) date to the Late Triassic. That’s between 237 million and 201 million years ago. They were smaller than the later sauropods. But they were far from puny. The animals weighed in at an estimated 7 to 10 metric tons. That’s larger than an African elephant!

All four specimens showed a similar set of features. But they didn’t match sauropods and other sauropodomorphs. Instead of upright, pillarlike legs, the dinosaurs had crouched hind limbs. Their front limbs were flexed, with elbows splayed slightly outward. Growth patterns in the fossil bones suggest the animals grew in seasonal spurts rather than steadily. And when their bones grew, they did so unusually fast, Apaldetti says. The growth rate was “even higher than that of the giants that grew continuously.”

These features show there’s more than one way to build a giant dino, her team concludes. It published its findings online July 9, 2018 in Nature Ecology and Evolution.

I. prima and L. sauropoides shared some features with later sauropods, though. One was a respiratory system that appears similar to that of birds. The researchers found air sacs within the animals’ vertebrae. These sacs would have held large pockets of oxygen-rich air. They likely helped the dinos keep cool despite their large size. And they made the animals’ vertebrae lighter.

Martin Sander is a vertebrate paleontologist. He works at Universität-Bonn in Germany. He says I. prima presents the best evidence yet of this birdlike respiratory system in sauropodomorphs. Scientists previously weren’t sure. But he isn’t convinced that the Lessemsauridae show a distinct path to massive size. “For me, it’s more of an intermediate stage,” Sander says.

That sentiment is echoed by Jeffrey Wilson. He is a vertebrate paleontologist at the University of Michigan in Ann Arbor. He agrees that Lessemsauridae bone growth was cyclical. But the cycles weren’t necessarily seasonal, Wilson points out. There may have been long growth spurts with fewer lags. That could be a step toward the steady growth seen in sauropods, Wilson says.

The Lessemsauridae lived some 30 million years earlier than Jurassic sauropods, such as Brachiosaurus and Diplodocus. So their growth strategy came first, Apaldetti notes. But ultimately, the Jurassic giants “were more successful,” she says. They outweighed the sauropodomorphs by as much as 60 tons. And they outlived them by tens of millions of years.

[saddinosaurfacts]

TITANOSAURUS “Titanic lizard” Late Cretaceous, 70 million years ago

Titanosaurus is a genus of extremely large sauropod dinosaur, once applied to a wide variety of species, but now only encompassing two (T. indicus and T. blandfordi). It gives its name, however, to the group Titanosauria, which includes the largest dinosaur ever found, Patagotitan, along with Argentinosaurus, Isisaurus, Rapetosaurus, and many others.

Oh, uh, a punchline... right. Um. It sounds like... “tight... anus... sore?”

Yeah, I'm not proud of that one, either.