Paleo 419 Lab 6

Order Pterosauria characteristics

• one of three vertebrate groups to evolve true flight

• novel bone in the forelimbs called the pteroid

• manual digit IV length greater than or equal to 50% of total forelimb length

Order Pterosauria historic groups

“rhamphorhynchoids” (Paraphyletic) and the pterodactyloid

Order Pterosauria Sister group

Lagerpetidae (a clade of basal avemetatarsalians)

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Darwinopterus, Order Pterosauria

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Ixalerpeton, Order Pterosauria

Family Ramphorhynchidae (Order Pterosauria) characteristics

• generally small

• short metacarpals

• short necks

• long tails that were reinforced by elongate rod-like ligaments

• slender, pointed rostra

• long procumbent teeth

• Do swimming and terrestrial locomotion

What are family Ramphorhynchidae babies called?

flaplings

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Dorygnathus (family Ramphorhynchidae)

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Rhamphorhynchus (family Ramphorhynchidae)

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Rhamphorhynchus muensteri (family Ramphorhynchidae)

Suborder Pterodactyloidea (Order Pterosauria) characteristics

• external naris and antorbital fenestra have become confluent

• short tails

• brains are relatively larger than in rhamphorhynchids

• metacarpals are elongated

• metatarsals are shorter

• Reduced or lost their fifth toe

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Pterodactylus, Suborder Pterodactyloidea, Order Pterosauria

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Pterodactylus, Suborder Pterodactyloidea, Order Pterosauria

Clade Ornithocheiroidea (Suborder Pterodactyloidea, Order Pterosauria) characteristics

• open-ocean gliders

• Most had teeth

• wingspans in excess of one metre

• Azhdarchoidea and Pteranodontoide groups

Pteranodon (Clade Ornithocheiroidea, Suborder Pterodactyloidea) characteristics

• toothless

• wings 7m across

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Pteranodon (Clade Ornithocheiroidea, Suborder Pterodactyloidea)

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Pteranodon (Clade Ornithocheiroidea, Suborder Pterodactyloidea)

Nyctosaurus (Clade Ornithocheiroidea, Suborder Pterodactyloidea) characteristics

• toothless

• smaller form

• antler-like crest

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Nyctosaurus (Clade Ornithocheiroidea, Suborder Pterodactyloidea) characteristics

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Anhanguera (Clade Ornithocheiroidea, Suborder Pterodactyloidea) characteristics

Azhdarchoidea (Clade Ornithocheiroidea, Suborder Pterodactyloidea) characteristics

• includes Quetzalcoatlus, Hatzegopteryx, and Tapejara

• dominant pterosaurs of the Cretaceous

• lack teeth

• snout is deep with a huge external naris that rises above the level of the eye

• Well developed crests

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Sinopterus, Azhdarchoidea, Clade Ornithocheiroidea, Suborder Pterodactyloidea

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Quetzalcoatlus and Zheziangoperus (Sinopterus, Azhdarchoidea, Clade Ornithocheiroidea, Suborder Pterodactyloidea)

Bone?

Pterosaur cervical vertebrae (Order Pterosauria)

Dinosauromorpha Characteristics

• one of the two branches of the Avemetatarsalia (the other being the pterosaurs)

• upright posture

• parasagittal gait (movement that is parallel to the vertebral column)

• posterolateral portion of femoral head ventrally descended

• straight cnemial crest

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Velociraptor (Dinosauromorpha)

Silesauridae characteristics (sister group to Dinosauriformes)

• beaked lower jaw convergent on the jaws of ornithischians

• quadrupedal stance

• long neck and long legs

• Leaf shaped teeth

• Beak-like lower jaw

• Quadrupedal stance

Asilisaurus (Silesauridae) Characteristics

• anterior ascending flange (ascending process) of astragalus

• laminae (thin sheets of bone) in the vertebrae

• well-defined anterior trochanter on the femur

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Silesaurus, Silesauridae

Bone?

Sinraptor astragalus (Silesaurus)

Pink?

ascending process of astragalus (Sinraptor, Silesaurus)