The Remarkable Scutosaurus – Permian Giant

The Permian period lasted from 290 million years to 248 million years ago.  A major event during this part of the Palaeozoic was the formation of the super-continent of Pangaea.  Shifting continental plates had begun to create a single, huge landmass in Carboniferous times, but it was in the Permian that the supercontinent Pangea formed.  Pangaea was to last for over a 100 million years before beginning to break up in the Early Jurassic.  As the continental plates that make up the Earth’s crust are still moving today, the break up is continuing.  For example, the Atlantic ocean is getting a little wider each year, roughly at the same speed your finger nails grow.

The end of the Permian is marked by a mass extinction event, approximately 65% of all vertebrate families became extinct.  Amongst the casualties were the bizarre armoured Pareiasaurs, a group of strange looking reptiles, some of which grew to the size of cars.

Scutosaurus

One of the more advanced pareiasaurs was the enormous Scutosaurus.  At something like 3 metres long and weighing as much as 1,000 kilogrammes this animal was one of the largest land living animals to have ever existed when they roamed the dry, arid landscapes of the Permian supercontinent.

Scutosaurus had a squat body, strong, powerful legs, and a short tail that was too small to reach the ground.  The broad head had a large mouth and the animal was probably an unfussy grazer of coarse, plant material.  The large body supported a huge gut, a prerequisite if you are going to try to digest tough plant matter.

Thickened Skull

The skull was thickened and ornamented with bizarre knobs and bumps.  Ornamentations on the skull are a common feature of pareiasaurs, some smaller forms even evolved head shields, making them resemble horned dinosaurs such as Triceratops and Styracosaurus.

Scutosaurus was a very advanced Permian reptile, the legs of this animal did not sprawl out to the side like other reptiles.  Instead they were directly under the body, supporting the animal’s great weight.  This stance and gait made Scutosaurus a very efficient walker and these animals may have migrated long distances in search of food to fill their enormous stomachs.

When the fossil record is examined, the pareiasaurs seem to have evolved and diversified very quickly towards the end of the Permian, perhaps exploiting the environmental niches left vacant as other genera died out.  Scientists have estimated that there may have been dozens of different genera.  Then, as quickly as they appear in the fossil record, they all disappear, it seems that no pareiasaurs survived into the Mesozoic.  Some palaeontologists refer to ancient reptiles like Scutosaurus as fossil record light bulbs – they shine very brightly, but briefly in the fossil record, before like a light bulb, burning out and disappearing forever.

A Scale Model of Scutosaurus

Scutosaurus.

Picture credit: Everything Dinosaur

To view the huge range of prehistoric animal models and figures available from Everything Dinosaur: Dinosaur and Prehistoric Animal Models.

Naming Female Dinosaurs – use “a” not “us”

Team members at Everything Dinosaur get asked all sorts of questions by young dinosaur fans when we are out and about visiting schools.  Now that most of the schools in the UK have broken up for the Summer holidays, the questioning does not stop, we get sent emails or we are cornered at a dinosaur event and put on the spot.

Our experts try to answer every enquiry the best they can and do follow them up, sending out more information if an a particular query requires it.  For example, one of our team members was asked the other day why Maiasaura had such a strange name compared to other dinosaurs.  Maiasaura was a Late Cretaceous hadrosaur (hadrosaurine, duck-billed dinosaur).

Fossils of this particular dinosaur have been found in North America and the animal is most closely associated with the Upper Cretaceous sediments at Two Medicine Formation near Choteau in western Montana.  On a visit to the area in 1978, the famous American palaeontologist Jack Horner was shown a collection of tiny dinosaur bones by a group of amateur fossil collectors.  Jack, recognised the remains as fossils of baby dinosaurs, and, when the location was fully explored, a fossilised nesting colony of Maiasaura was discovered.  This site in Montana has yielded over 200 individual specimens, ranging from unhatched eggs to fully sized adults.

A Scale Drawing of an Adult Maiasaura with a Nest

Picture credit: Everything Dinosaur

Dinosaurs

It seems that Maiasaura lived in large herds and migrated to favourite nesting sites to breed and raise their young, just like some modern birds.  Something like, fifteen individual nests were discovered by Jack Horner and his team, but the site itself is much larger with extensive fossil rich sediments to explore.  The Maiasaura built nests by piling together leaves and soil in a similar fashion to Alligators.  The rotting vegetation helped incubate the eggs.  When the eggs hatched the young stayed in the nest for sometime and depended on the parents to feed them (altricial behaviour).

Jack Horner and his colleagues estimated that the baby Maiasaura stayed in the nest for about one month.  Interestingly, the space between each nest on the Montana site was quite uniform.  There was approximately 7 metres between each one, just about enough room for an adult Maiasaura to squat next to her nest to guard it.  This type of formation is found in many sea bird nesting colonies today.

Questions About Dinosaurs

As Maiasaura is associated with a nesting colony and altricial behaviour she was named “Good Mother Lizard” and since it was suggested that the majority of adult skeletons associated with the site were female, Maiasaura was given the female gender for her name.  The female form is “saura” and the male, more commonly used format is “saurus”.  This is why Maiasaura has an unusual ending to her name (binomial name M. peeblesorum).

The Scale Model of Maiasaura by Carnegie Safari

Model of “Good Mother Lizard”.

Picture credit: Everything Dinosaur.

Maiasaura is represented in the modelling world by a super replica from Carnegie Safari.  When the model was first introduced, (Carnegie Collectibles Maiasaura dinosaur), the adult Maiasaura was depicted sitting on her nest.  This was not an accurate representation, a fully grown Maiasaura would have crushed any eggs she sat on.  The model makers introduced a second model showing the mother Maiasaura and her eggs separately.

To view the prehistoric animal models and figures in the Wild Safari range: Safari Ltd. Wild Safari Prehistoric World Models and Figures.

The only other dinosaur with the female form to her name that we can think of is the small dinosaur Leaellynasaura, associated with polar deposits in the southern hemisphere.  This dinosaur was named by husband and wife palaeontologists Tom and Patricia Rich after their daughter Leaellyn.