dinosaursmodeoflife
Post on 22-May-2015
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Dinosaurs
I.G. Kenyon
How Many Dinosaur Species? More than 500 Genera
Approximately 1,000 species
Herbivorous V Carnivorous
Dromaeosarus albertensis
Study of dinosaur morphology-mode of life may be established
Uniformitarianism – study of modes of life of modern herbivores and carnivores and predator-prey relationships help to infer the
niches that dinosaurs occupied in the Mesozoic ecosystems
Bipedal – fast/agile runnersLong balanced tail for turning at speed
Large brain body mass ratioLarge forward facing eyes
Endothermic-covered in feathersStrong jaws with sharp teeth
Sharp claws on forelimbs/feet for slashing preyMay have hunted in pairs or packs
Evidence for Carniverous
Carnivorous Dinosaurs
Flexible base to tail
Large forward facing eyes Bipedal , fast, agile
walked/ran on tiptoe
Carnivorous Dinosaurs
Tail carried upright aids manoeuvrability and
change of direction when running at high speed
Strong skull with powerful jaws and sharp teeth
Sharp claws on fore limbs for
slashing prey
Carnivorous DinosaursCovered in feathers to keep warm
and maintain a high metabolic rate? Probably warm blooded
Sharp claw on second toe of foot used for
slashing at preyMay have hunted in pairs or packs
Spinosaurus – The Largest Carnivore?
12.6 to 18 metres in length
Weighed 7.0 to 20.9 tonnes
Cretaceous 97-112 Ma
Lived on land and in water like a modern crocodile
Mainly a fish eater and had vertebrae extensions covered
with skin to form a sail-like structure on its back
Large body massQuadrupeds/4 legged
Spikes, nobbly bits, horns for defenceHorny beaks with small/no front teeth
Neck lengths varied according to type of grazerGastroliths found inside the stomachs
Lived in large herds/Juveniles shielded on the insideSmall brain to body mass ratio
Evidence for Herbiverous
Evidence for Herbiverous - StegasaurusShort neck and small head
probably grazed bushes close to the ground
Grazed in herds much like elephants do today
on the plains of Africa
Walnut sized brain!
Four legged, bulky and heavy about the size of a double decker bus
Heavily armoured, plates on back may have been thermo-regulatory
Evidence for Herbiverous - Stegasaurus
Toothless beak and small cheek teeth
Sharp tail spikes to swing for protection
Late Jurassic 150 to
155 Ma
Gastroliths (Stomach Stones)
Psittacosaurus fossil with gastroliths in its stomach region, American Museum of Natural History
Psittacosaurus
Many herbivores swallowed stones (gastroliths) to help break down tough, fibrous plant
material in their stomachs
Over time the stones became very smooth and polished
Yummy! Rock Cakes on the menu again!
Herbivorous Dinosaurs
Argentinosaurus – The Largest?
Argentinosaurus – The Largest?
Incomplete Argentinosaurus femur shaft measuring 1.18 metres long
From this it is estimated that the animal must have been
between 30 and 35 metres in length
The animal is thought to have weighed 80 to 100 tonnes
Late Cenomanian (Cretaceous)
94 – 96 million years old
Argentinosaurus – The Largest?Kingdom Animalia
Phylum ChordataClass ReptiliaNode DinosauriaOrder SaurischiaSub-Order SauropodomorphaBranch TitanosauriaFamily AntarctosauridaeGenus ArgentinosaurusSpecies huinculensis
Skeletal reconstruction in the Senckenberg Museum, Germany
Relative Sizes – Dinosaurs, Elephants, Man
Herbivorous dinosaurs – the largest creatures ever?
Not quite, the Blue Whale today is the largest creature ever to live
weighing 180 tonnes and 30m long
Humans 7.4 – 7.8Bottlenose Dolphin 4.14Chimpanzee 2.2 – 2.5Dog 1.2Cat 1.0Sheep 0.8Rabbit 0.4
A more complex version of the brain to body mass
ratio
That’s All
Folks!
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