are vertebrates, tetrapodes, amniotes, diapsids, and archosaurs-- dinosaurs are a particular branch in the tree of life, we are on another. the list above is like the "address" of dinosaurs in this tree. 

"dino" comes from the greek word deino, fearfully great or terrible

"saur" comes from the greek word sauros (sauras) lizard or reptile

archosauria

fascinating features of crocidilians that they share with birds,

like... they exhibited parental care

nests & parental care, not so surprising

they lay eggs because they come after amniotes on the tree of life

the archosaur revolution

permian, right before triassic, right before mesozoic

early mesozoic innovation..... they are starting to become bipedal, hip and femur modifications, perferated asitabulum, 

which are more closesly related to crocs and birds and which are more croc?

ankle innovations in archosauria, much stronger more rigid, indiciates high activity levels, rearrangement of leg bones and muscles, these innovations set the strage for origin much larger, stronger animals, and new forms of locomotion

 ankle joint, mesotarsal ankle... crurotarsal ankle, 

snynapomorphy is the ankle joint... can be found in all later dinosaurs

PTEROSAURS

are not dinosaurs and why?

diversity is extreme but extremely late... into the age of dinosaurs, they lack apomorphies of dinosaurs so they are not part of that single branch, so how about the flight? it's homoplastic, convergent evolution, they actually fly differently than birds, (they fly with their fingers and membranes and flaps).... 

LAGOSUCHUS

closest outgroup to dinosaurs?  and why?

partially open hole in pelvis (avetabulum), 

(hole in plevis completely open= dinosauria)

stronger hips and powerful legs (stronger hip girdle, site of muscle attachment larger),

on pelvic bones and sacral vertebrae

greater stregnth, more active lifestyle... 

next features, specilzation front limbs, individual fingers, hands not used for locomotion, offset thumb allows for grasping, elbow in close to the body-- bird like foot, three forward facing toes, primary contacting ground, 

earliest dino fossils, late triassic rocks,

what were earliest dinos like?

name one and its synapomorphies 

earliest known dinosaurs are small, bipedal carnivores from triassic, 

Eoraraptor, dawn thief, .....about 3 ft long, arms short, hand delicate, sharp claws, anatomy very unspecialized relative to later dinosaurs, relatively small hip bones, smaller leg muscles and relatively short neck 

problem of the plesiomorphy, direction of pubis in saurischia, maybe just outside dinos or deep in saurischia, ... 

intro to major groups of dinosaurs

saurischia and ornithischia, 

are idenitified bu their different pelvic regions-

how so?

the pubis points forward and the ischium points back in saurischians. 

the pubis runs parallel with the ischium and there is an additional process in front in ornithischians.

bird hipped... convergence - homeplasy! 

three major groups- 

thyrephora, armored, quadrupedeled planter eaters like stegosaurs...

duckbills, bird footed, bipedal, some quadraupedal herbivores

marginocephalias, hard head or bone head dinosaurs and the horned dinosaurs, like tricepatops

an in-turned femoral head, an oppostable thumb, a perforate acetabulum, and an s-shaped neck

the address of this branch in the tree of life is partially described as located in a series of internested groups (amniota, tetrapoda, diapsida, archosauria)

ORNITHIschia, the bird hipped dinos (more distant from birds than Trex though)

an early ornithischian... synapomorphies... 

Lesothosaurus, E Jurassic, South Africa, small animal, bipedal--- earliest ornithischian is known from the triassic of argentina.... the backward tipped pelvis, also the predentary bone related to diet and on lower jaw, for herbivores...

E Jurassic, 3-6 ft, from So Africa, "different kinds of teeth", long fang like teeth at front of mouth as an apomorphy, teeth mesh, enlarged cheeks, larger muscle cheeks

speculation of fangs- omnivorous diet? predetor defense? mate competition? display of mate quality?

ossified tendons, make the toros and tail more rigid, may have aided in balance when running, related to supporting the enlarged gut 

"bird footed" dinos, refers to three forward facing toes

is a monopheletic group, - large and very successful group, species rich, known throughout mesozoic, but follow same pattern as in other lineages, best known from cretaceous, during cretacious herbivores?

synapomorphy- jaw joint lies below level of mandibular tooth row, linked to the mechanis of jaw movement, important for chewing, trend- loss of antorbital fenestra

different reconstructions, evidence of feathers in ornithischian dinos? Dryosaurus for example, probably had feathers.... maybe not lol

no evidence of scales, with two weird exceptions in all of Ornithischia, hadrosaur skin.... 

latest cretaceous, right before the extinction event, retains a lot of plesiomorphic characters, features seen in the earliest parts of ornithopoda, why did these stick around for 100 mill years? we don't know... 

recognize the skull? trend small or loss of antorbital fenestra, the jaw joints  is articulating with the lower- jaw joint lies below level of mandibular tooth row... predentary bone

Tenontosaurs, creataceous of North America, hooflike hand claws, trend in ornithopoda, developing more ossified tendons, also may be related to larger body size,,, quadrupedal but with front legs shorter, not efficient for long distances... but true lived in larger herds, probably migrated and used strength in numbers as defense

 very early described dinosaur... evidence of bipidality of dinosaurs... 

facultative quadrupeds- forelimbs in slow locomotion, browsing for plants, but at higher speeds- bipedal 

Synapomorphies can be lost--example, bipedality lost, carnivory lost, antorbital fenestra lost... 

 duckbilled dinosaurs, common in late cretaceous of europe, asia and north america, 

novelities: **complex dental battery (specialized teeth that expand and form for grinding), complete loss of antorbital fenestra, two groups- one with hollow crests (Lambeosaurinae) and one without that's flatheaded (hadrosarinae)

swinging jaw movement more efficient.. 

ps why the crest? 

resonating chamber allowing Lambeosarine hadrosaurids to make deep loud sounds, maybe warned of predators, or kept a herd together, or attracted potential mates, or all of these things

sheild bearer, armored dinosaurs

contains some famous dinso, stegosaurus, synapomorphy, one or more rows of armored plates along back, run parallel to vertebral column, embedded in skin

earliest thyreophorans, eary jurassic, more than 300 plates along back, problem we don't know exactly where they were. 

early jurassic to end cretaceous, 

elongation of skull, elongation of bony plates along vertebrae, reduction in bony plates elsewhere on body...

diversity, mostly about the form of spikes

stegosaurian lifestyle, movement slow, lumbering creatures... diet, herbivores browsing low vegetarian, social life, probably NOT herding animals, based on footprint and skeletal evidence

bizarre plates-- no doubt tail spikes had a defensive purpose, earlist hyptheses for plates on body was defense against large predetors, but too lightly built for defense... more recently? heat exchange? or act like solar panels to soak up heat? but bone structure...

according to newer uc berkley research, maybe helpedc these dinosaurs spot members of their own species 

synapomorphy, scutes interlock t form extensive body armor that extends to the head. most diversity is in the shape and position of armor and tail weaponry...

huge tail club, wide head with plates fused to skull, 

know defense within ornithsischians

means skull head, refers to projection of bone on the back of the skull, most evolutionary action in head

two grousps did very different things with heads... 

synapomorphy - shelf on rear of skull, composed primarily of squamosal bone... 

huge shelf

all bipedal (not derived, inherited)

most small - up to 10 ft

largest medium sized group

not very species rich

all known from cretatceous of n am, europe asia

- fossil record almost entirely made of skulls, very unsual for dinos, opposite of sauropods... skull bones very thick but overall small lightly built animals...

snyaopmorphy- reall thickened skulls. 

why big skulls? head butting? no.... too light and frail 

but maybe demonstrating mate quality or for species recognition

"horned" very diverse, no hones in early parts, large horns on many overall, early from late jurassic, eurasion and no america, species rich for a short time

Rostral bone, small bone at tip of jaw, in front of the premaxilla, not found in any other dinosaur --trend... small to large body, bidpedal to quadrapedal..

perhaps adult to juvenile creates bony dome difference 

next groupf marginocephlia is ceratopsia

 means "horned" larges horns present on many, but no horns in early parts

another late group, earlist from jurassica, reached greatest diversity during late cretacious , eurasian and north american, very rich species, in NA, 70% of all fossils are ceratopsian in the late cretaceous 

synapomorhpy-- rostral bone, small bone at tip of jaw, in from on premaxilla,not found in any other dinosaur

early ceratopsians, small to large body size, bipedal to quadrupel, early certaopsians, (eg Psittacosaurus) they are quadrapedel is that plesiomorphic? 

 primarily bipedal, quadrapedal perhaps while feeding, very small and lightly built, predentary bone includes it in ornithiscia, no appreciable horns or frills, develop a form of vertical grinding, not the specialized movement seen in ornithopoda, what else? the back turned pubis, another synapormorphy of ornoth, 

early cretaceous/late jurassic, of asia, mongolia, china, many complete articulated skeletons, many on the black market, small dino, less than 2 m --- they have bristles on the tail?? birds are not in ornithiscia, so these guys are distant cousins of birds... bristle like proto feather?

larger, 4-8 m long, exclusively from north america, all late cretaceous, very large skulls with very large frills, largest skulls of any land animal skulls almost 8 ft long, dental batteries-- clear case evolutionary convergence, different from ornithopods, teeth worked like scissors, sharp edges that would have chopped, lived in herds (two forms of evidence- trackways and mass death assemblages)

diversity- two groups of neoceratopsians which are distinguished by horns and frills do not need to know for exm

why horns and frills? 

-defense? (but some spikes and spines don't seem to serve as a defensive function)

-regulate body temperature? old hypothesis, because they were probably more closely related to crocs and birds, not lizards, they had a 4 chambered heart, etc. 

- ** sexual selection? large surface area could have been highly colored, other options-- species recognition to find right mate and have more offspring, ornamentation could be display mate quality for female choice, or perhaps to establish dominance among males like in competition

sexual selection is a special case of natural selection, which tends to produce individuals that are well adapted to their environment, does not adapt the individual to the environment but does enhance traits involved in mate acquisition-- also perhaps for female choice based on elaborate ornamnetation... or for male competition in which males compete for territory or access to females or areas on mating grounds where displays take place

**synapomorphies of SAURISCHIA 

long cervical vertebrea

long hand, with digit 2 the longest 

large claw on thumb digit 1

ex. prosauropoda

--pachycephalosaurs

--ceratopsians 

some extremes, largest land animals of all time, largest and heaviest and tallest

130+ feet or 40m and 18 m high

55 tons

remember or recognize hip structure- (first of the two groups of saurischian dinosaurs, other is therapoda, which includes birds, so these extreme dinos are closer related to birds)

thus these biggest of dinosaurs are more closely related to birds than ornithischian dinos like stegosaurus

synapomorphies- blunt closely packed teeth, change indicates modifications in response to a dietary shift to eating plants-- tibia shorter than femur

"headless dinosaur" 

fossil record is unusual - most bones are huge heavilty built and common in fossil record

but skulls are tiny and fragile, attachment between skull and first vertebra very weak

thus skulls often detach after death and are very rare in the fossil record (40 complete skulls total for most species, for most species none)

the two major lineages (deepest split)

--Prosauropoda (plateosaurus)

--Sauropoda

 the triassic plateosaurus

earliest known sauropodomophs parts of this group

indicate just few million years after very earliest dinos (such as eoraptor) already at least sometimes quadrupedal and herbivorous -- rapid evolutionary change from carniverous ancestors 

so platesaurus-- anatomy prosauropods "transitional" to large more familiar sauropoda

triassic of germany, france - first discovered dinos

**synapomorphies--

nares shifted to dorsal surface of skull

great reduction in number of phalanges of hand, only digit 1 retains a claw, presacral vertebra greatly lightened by pleurocoels (holes)

quadrapedal/

why the long neck? food resource partionining?

Diplodocid diversity- apatasaurus: most famous diplodocial aka brontosaurus, named during bone wars

name means "deceptive reptile" short and heavier than diplodocus marsh named brontosaurus and cope? or pope? named it apatosaurus

cretaceous south america, diplodocid sauropod, record lenghth 70 ft high and 130 ft long, length inferred from size of vertebrae and how dino bones are scaled

diaphram, palatal teeth lost, 

four chambered heart, enlarged brain, 

nest building behavior and care of young

in turned femoral head

opposable thumb

perforate acetabulum

s-shaped neck

long cervical vertebrae

long hand, with digit II the longest

large claw on thumb (digit 1)

blunt closely packed teeth

tibia short than femur

nares shift to dorsal of skull

presacral vertebra greatly lightened by pluerocoels

great reduction in number of phalanges= 

only digit 1 retains a claw

kenetic flex jaw

deep ball in socket joint between head and neck

digit V lost from hand (4 fingered)

phalanges of digit V of foot lost

digit 1 of foot reduced and no longer connects to ankle joint

hollow thin willed tubular bones

fused clavicles (furcula)

tooth row positioned entirely in front of orbit

maxillary fenestra present

digit IV lost from hands (3 fingered)

astragalus overlaps tibia

semilunate carpal present

long slender hands

protofeathers present

distal 3/4 of tail stiff

forelimb at leas 3/4 length of presacral vertebral column

ossified sternal plates

front part of pubic boot absent

brooding behavior

long pinnate arms feathers present

flight

forelimb longer than hindlimb

asymmetrically veined wing feathers 

pines, spruces, junipers

tough needles with cuticle

300-400 species 

diverse in cooler environments

abundant in mesozoic

now mostly in tropic areas

cones in center of plant

each plant is male or female

reproduce with flowers

seed covered with fruity flesh

dominant plant 

1000s alive today

teeth inset from margin of jaws

predentary bone in lower jaw

in turned femoral head

opposable thumb

perforate acetabulum

s-shaped neck

pelvis with back turned pubis

predentary bone in lower jaw

ossified tendons along part of vertebral column

teeth inset from margin of jaws 

(indicating the presence of muscular cheeks)

armor made of bony scutes that cover back and or flankes

tibia short than femur

thickened skull "dome" surrounded by bumps

occipital plate rotated beneath skull