#malawisaurus

[loveofjuniper]

malawisaurus in the style of madalitso band, my favourite malawian musicians

[randomanimaloftheday]

Day 200#: Malawisaurus dixeyi

Merry day twenty-nine of Dino-December! Today's animal of the day is Malawisaurus dixeyi!

Photo credit: zoome3 on DeviantArt

This surprisingly small species of sauropod dinosaur lived during the Early Cretaceous period, and as its name suggests, was found in what is now northern Malawi. Malawisaurus was actually originally described as a species of Gigantosaurus back in 1928. This is dubious genus of sauropod dinosaur with a VERY complicated history, not to be confused with Giganotosaurus. It's a LONG story, and actually really sick right now, so I'm going to save the details for when I cover Tornieria. Like I said before, Malawisaurus was rather small for a sauropod, though it's definitely not the smallest. When it was first described, it was estimated to be around 49 ft long and was thought to weigh around 11 tons, but a 2020 study reduced its size estimate to around 36 ft long and only 3.1 tons.

Image credit: cisiopurple on DeviantArt

Despite its small size, Malawisaurus was actually a member of titanosauria, which also included some of the largest sauropods/land animals/animals in general to ever live, like Patagotitan and Argentinosaurus (which I talked about on day 19#). However, unlike many of these giant dinosaurs, Malawisaurus is actually one of the few species of titanosaurs that we have a skull of, likely due to its small size, since, as we've discussed before, larger animals don't tend to fossilize as well compared to smaller creatures. Malawisaurus was actually an early member of a derived clade of titanosaurs known as lithostrotia, which means "inlaid with stones" since many of these dinosaurs possessed armor-like osteoderms on their backs.

[a-dinosaur-a-day]

Malawisaurus dixeyi

By Ripley Cook 

Etymology: Reptile from Malawi

First Described By: Jacobs et al., 1993

Classification: Dinosauromorpha, Dinosauriformes, Dracohors, Dinosauria, Saurischia, Eusaurischia, Sauropodomorpha, Bagualosauria, Plateosauria, Massopoda, Sauropodiformes, Anchisauria, Sauropoda, Gravisauria, Eusauropoda, Neosauropoda, Macronaria, Titanosauriformes, Somphospondyli, Titanosauria, Lithostrotia

Status: Extinct

Time and Place: Sometime between 125 and 113 million years ago, in the Aptian age of the Early Cretaceous 

Malawisaurus is known from the Upper Member of the Dinosaur Beds Formation in Mwakasyunguti, Malawi 

Physical Description: Malawisaurus was a titanosaur - the kind of heavy-set, bulky sauropods that dominated the Cretaceous landscape. Though it did not get as big as its relatives, it is among the group of the largest land animals to walk the earth. Still, Malawisaurus was on the smaller size, probably only reaching 4.7 tons, and maybe around 16 meters long. Malawisaurus had a long neck and tail, and a distinctively short, squat, and squarish head - with very large nasal holes in the skull. This would have helped to keep its skull relatively cool, an important feature for a large animal in a hot and humid climate. 

By Slate Weasel, in the Public Domain 

Despite having fossil material of the skull and teeth - a rarity for titanosaurs - redescriptions and reexaminations of Malawisaurus have shown that the wealth of material assigned to it might not all be one species, so studies to clear up the picture are ongoing. For now, it seems as though there were two distinct morphs of Malawisaurus, differing based on variations in the vertebrae of the neck. The tail vertebrae also had very long connections between one another, that would have made its tail a little more stiff - possibly for balance. There were also depressions in some of the sides of the vertebrae, though it’s uncertain what they would have been for.

The braincase of Malawisaurus has been thoroughly studied, helping us to understand more about its brain and, thus, behavior. Malawisaurus had a very large semicircular canal, like other early titanosaurs. It also had a nerve for the eye much more to the side than seen in other sauropods. Malawisaurus had thick, peg-like teeth, which would have aided in stripping leaves from branches. 

By Mesozoical, CC BY-SA 3.0 

As a Titanosaur, it would have been largely scaly; it possible it may have had small scutes covering the skin to aid in protecting its body from predators.

Diet: Malawisaurus would have been a medium-level browser of plant material.

Behavior: Based on the head of Malawisaurus, it would have probably moved its neck and head slowly from side to side, rather than quickly; this would have made it very sluggish as it moved its head along the plant level to browse, though this probably would have worked out, as it had to eat a lot of plant material every day to keep its size up. This means it would have browsed, slowly and surely, through the row of leaves, before moving on to the next one. Malawisaurus would have probably maintained a fairly active metabolism through sheer body size, and would have needed to eat a lot of plant material to uphold itself each day. It would have moved its eyes only a little to see more of the area around it from side to side, similar to its relative Sarmientosaurus. This means that it also would have moved its eyes slowly, in addition to its head and neck. 

By José Carlos Cortés

Malawisaurus probably wouldn’t have been the fastest of dinosaurs in general, though of course it’s difficult to tell for certain. It was probably fairly common, too, and may have lived in herds. Whether or not it would have been involved in any parental care is uncertain, though it probably would have laid its eggs in mounds like other titanosaurs.

Ecosystem: Malawisaurus is known from the Dinosaur Beds Environment, a habitat of a river bed flowing from a series of lakes. This was an iron-rich muddy environment near the rivers that transitioned to a more sandy habitat near the lakes, with the entire ecosystem being in a somewhat more temperate climate - being fairly far from the equator. Still, a lack of major palynological studies leaves us wondering what sorts of plants were in the area. Here there were a wide variety of crustaceans, frogs, and ray-finned fish, as well as the turtle Platycheloides, the notosuchian Malawisuchus, and another titanosaur, Karongasaurus. There seems to have been a third type of dinosaur, possibly another kind of Malawisaurus as per the two morphs - indicating the presence of a diverse, but endemic, clade of sauropods in this environment. So, clearly, there was enough plant material to feed at least three large dinosaurs; hopefully one day we’ll know exactly what.  

By Scott Reid 

Other: The braincase of Malawisaurus indicates it was a basal titanosaur, being closer to the base of the evolutionary tree for this group. It is one of the only titanosaurs for whom a skull is known; which makes the skeleton being kind of useless all the sadder.

~ By Meig Dickson

Sources under the Cut 

Andrezejewski, K., M. J. Polcyn, D. A. Winkler, E. G. Chindebvu, L. L. Jacobs. 2019. The braincase of Malawisaurus dixeyi (Sauropoda: Titanosauria): A 3D Reconstruction of the brain endocast and inner ear. PLoS ONE 14 (2): e0211423.

Dixey, F. 1925. The discovery of fossil reptiles. Annual Report of the Geological Survey Department for the Year 1924, Nyasaland Protectorate 1924:7

Gomani, E. M. 1999. Sauropod caudal vertebrae from Malawi, Africa. In Y. Tomida, T. H. Rich, and P. Vickers-Rich (eds.), Proceedings of the Second Gondwanan Dinosaur Symposium, National Science Museum Monographs 15:235-248

Gorscak, E. 2016. Descriptive and Comparative Morphology of African Titanosaurian Sauropods: New Information on the Evolution of Cretaceous African Continental Faunas. A dissertation presented to the faculty of the College of Arts and Sciences of Ohio University.

Filippi, L. S., L. Salgado, A. C. Garrido. 2019. A new giant basal titanosaur sauropod in the Upper Cretaceous (Coniacian) of the Neuquén Basin, Argentina. Cretaceous Research 100: 61 - 81.

Haughton, S. H. 1928. On some reptilian remains from the Dinosaur Beds of Nyasaland. Transactions of the Royal Society of South Africa 16:67-75

Jacobs, L. L., D. A. Winkler, Z.M. Kaufulu and W.R. Downs. 1990. The Dinosaur Beds of northern Malawi, Africa. National Geographic Research 6(2):196-204

Jacobs, L. L., D. A. Winkler, W. R. Downs and E. M. Gomani. 1993. New material of an Early Cretaceous titanosaurid sauropod dinosaur from Malawi. Palaeontology 36(3):523-534 \

Paul, Gregory S. (2010) The Princeton Field Guide to Dinosaurs.

Tidwell, V., Carpenter, K. & Meyer, S. 2001. New Titanosauriform (Sauropoda) from the Poison Strip Member of the Cedar Mountain Formation (Lower Cretaceous), Utah. In: Mesozoic Vertebrate Life. D. H. Tanke & K. Carpenter (eds.). Indiana University Press, Eds. D.H. Tanke & K. Carpenter. Indiana University Press. 139-165.

[a-dinosaur-a-day]

Malawisaurus here with a Chanukah gift for YOU!

[malorisaurus]

Doing my best to confuse everyone by changing both my username and profile picture today. 😌

[clarasew-blog]

Malawisaurus! I had a quick tour around the awesome Karonga museum whilst on a field trip up there, great mix of geology and modern local history; fact of the day birds are descended from dinosaurs #karonga #malawi #museum #dinosaurs #malawisaurus #factoftheday #fieldtrip #history (at Karonga, Malawi)

[a-dinosaur-a-day]

Malawisaurus dixeyi

Source: http://dinosauralive.wikia.com/wiki/Malawisaurus

Name: Malawisaurus dixeyi

Name Meaning: Malawi Reptile

First Described: 1993

Described By: Jacobs et al. 

Classification: Dinosauria, Saurischia, Eusaurischia, Sauropodomorpha, Plateosauria, Massopoda, Sauropodiformes, Anchisauria, Sauropoda, Gravisauria, Eusauropoda, Neosauropoda, Macronaria, Titanosauriformes, Somphospondyli, Titanosauria, Lithostrotia

Malawisaurus is a titanosaur that at the very least is known from a skull. Seriously. Very few titanosaurs have known skulls. It’s ridiculous. So that’s definitely, actually, in all reality what its head looked like. A miracle. 

Source: https://en.wikipedia.org/wiki/Malawisaurus

It was only about 16 meters long and it has been found with structures that may have been scutes covering the skin like many later titanosaurs. It was found in the Dinosaur Beds Formation in Malawi, and lived in the Aptian age of the Early Cretaceous, sometime between 125 and 113 million years ago. 

Sources: 

http://www.prehistoric-wildlife.com/species/m/malawisaurus.html

https://en.wikipedia.org/wiki/Malawisaurus

Shout out goes to @diazeheather!

[palaeopedia]

Malawi lizard, Malawisaurus (1993)

Phylum : Chordata Class : Reptilia Order : Saurischia Suborder : Sauropodomorpha Superfamily : Titanosauroidea Genus : Malawisaurus Species : M. dixeyi

Early Cretaceous (125 - 115 Ma)

16 m long and 12 000 kg (size)

Africa (map)

Malawisaurus was a genus of sauropod dinosaur (specifically a titanosaurid). It lived in what is now Africa, specifically Malawi, during the Aptian age of the Early Cretaceous Period. It is one of the few titanosaurs for which skull material has been found.

It was named by Louis L. Jacobs and colleagues, and was originally described in 1928 by Sidney H. Haughton as a species of Gigantosaurus (an invalid name for the diplodocid currently known as Tornieria). Haughton considered it closely related to the species G.robustus (later the type species of Janenschia). They are currently recognised as separate but related forms of titanosaur.

Relatively small by sauropod standards, Malawisaurus reached lengths of around 16 metres. Like some other titanosaurs, ossicles have been found which are believed to represent dermal scutes that covered the skin.

The vertebrae from the middle part of its tail had elongated centra. Malawisaurus had vertebral lateral fossae that resembled shallow depressions. Fossae that similarly resemble shallow depressions are known from Saltasaurus, Alamosaurus, Aeolosaurus, and Gondwanatitan. Venenosaurus also had depression-like fossae, but its "depressions" penetrated deeper into the vertebrae, were divided into two chambers, and extend farther into the vertebral columns.