GEOL 305 midterm 2
Ch 8.2: Know, for the ceratopsian clade, the following info and characteristics: skull, horns, chewing apparatus, digestion
Narrow skull Skull that flared deeply in the cheek region Hooked beak at front of mouth from presence of a rostral bone on the upper jaw, unique to this clade Many ceratopsians had horns. The horns you see on fossil skulls are simply the bony horn cores. In living ceratopsians those would have been covered in a keratin sheath, making them much larger in real life that it appears from the fossil skulls. Hooked rhamphotheca Blocks of cheek teeth in both upper and lower jaws A sturdy coronoid process Evidence for the existence of fleshy cheeks
Ch 6: diagnostic characteristics which all ornithischian dinosaurs share
1. At least part of the pubis has been rotated backward to lie close to the ischium; this orientation is called opisthopubic. 2. A predentary: an unpaired, scoop-shaped bone that capped the front of the lower jaw. Both of these adaptations were associated with food consumption and processing. 3. Toothless, roughened front tip of the snout 4. A narrow bone that crossed the outside of the eye socket (the palpebral) 5. A jaw joint which is set below the level of the upper tooth row 6. Cheek teeth (molars) with low crowns which are somewhat triangular in shape 7. Five or more vertebrae in the sacrum (which connects to the pelvis) 8. Ossified tendons above the sacral region (and usually further along the vertebral column) for stiffening the backbone.
Ch 9: know the fossil record of Ornithopods eggs, and nesting sites
A small, basal ornithopod, Orodromeus, has hatchlings which had well-developed limb bones, with fully formed joints, and thus the hatchlings must have been able to move as well as adultsEggshells in these nests have a minimum of breakage. Minimal parental care is thus inferred because the hatchlings must have left the nest quickly (so the egg shells weren't trampled). The hadrosaurids are known to have nested in colonies, digging a shallow hole in sediment and laying, in the case of Maiasaura, up to 17 eggs in each nest. Each nest had about an adult body length between them. Hatchlings are found in nests with the eggshells in numerous small fragments, implying a long stay in the nest with attendant parental care. Poorly developed limb bones and joints also point to the juvenile hadrosaurs being dependent on parental care. Hatchlings must have grown fast from a 1m hatchling to a 9m adult at ~ 12 cm per month, and would probably have had healthy appetites for which their parents had to supply food.
Lec 9: Ornithischian Genasauran Cerapoda Ornithipoda: Where found? What age range?
All Ornithopoda were herbivores and they are the most numerous, diverse, and longest-lived group of all the herbivorous Dinosaurs. From the Jurassic (their first appearance) until the end of the Cretaceous (when they went extinct), they evolved over 100 species (that we know of). Their geographic distribution covered the world, from the equator to land that is now close to the poles. This encompassed many diverse habitats and a wide range of climates. They evolved a range of sizes, from small (1-2m in length) at the beginning, to some very large (>12m length). Hypsilophodon, one of the smallest, was ~ 6 feet long from head to tip of tail, and weighed ~ 45 lbs.
Ch 9: know general facts about the Ornithopoda
All Ornithopoda were herbivores and they are the most numerous, diverse, and longest-lived group of all the Dinosaurs. From the Jurassic (their first appearance) until the end of the Cretaceous (when they went extinct), they evolved over 100 species (that we know of). Their geographic distribution covered the world, from the equator to land that is now close to the poles. This encompassed many diverse habitats and a wide range of climates. They evolved a range of sizes, from small (1-2m in length) at the beginning, to some very large (>12m length). But not all of the ornithopods are large, Hypsilophodon, one of the smallest, was ~ 6 feet long from head to tip of tail, and weighed ~ 45 lbs
Ch 8: understand the general characters of the Marginocephalia
All dinosaurs in Marginocephalia have a ridge, or shelf, of bone running across the back of the skull. The actual size and configuration of that bone can vary, but in every dinosaur in the clade, that bone prevents a view of the back of the skull when viewed from above (dorsal side).
Lec 11: What is distinctive about Amargasaurus? Age? Where found?
Amargasaurus was also from the southern hemisphere, from South America. You will remember that Africa and South America were still close to each other, and further south during this time than they are at present. We've looked at Amargasaurus before, remember it has the doubled elongate neural spines on the vertebrae of its neck and forward-most part of the torso, as seen in this photo of a mounted specimen. http://upload.wikimedia.org/wikipedia /commons/d/d0/Amargasaurus1_ Melb_Museum_email.jpg This genus is Early Cretaceous in age, and was one of the smaller sauropods at only ~ 33 feet in length. Whether the elongate neural spines supported a "sail" of skin or not is still being argued. The skull is very similar to other species within the Diplodocoidea, but more robustly built than that seen in Nigersaurus, and the front of the mouth is narrower, and rounded.
Lec 7: General characteristics of all Ankylosauria, age range, and geographic range
Ankylosauria facts: ● Mid-size dinosaurs, rarely more than 5 m in length ● Limbs different lengths, with hind limb as much as 150% of front limb length ● Global distribution; predominantly North American, but also found in Europe, China, Australia, South America, and Antarctica ● As a group, the Ankylosauria reached peak diversity in the Cretaceous
Lec 11: Diplodocus and Apatosaurus: be able to recognize and know what age and where found. What are their heads and teeth like?
Apatosaurus' close relation, Diplodocus had more lightly built hind-limbs, and shorter neural spines on its vertebrae. The skull is very similar. Diplodocus is also from the Late Jurassic in western North America. It is one of the most common fossils to be found in the Upper Morrison Formation.
ch 8.1: Know, for the Pachycephalosauria clade the morphological characteristics and change in head shape and ornament through differing life stages
Bipedal ornithischians Thickened skull roof In North America skull had high domes Several genera/species have flattened, yet thickened skulls, but some paleontologists consider them juvenile forms of the fully dome-headed forms.
Where and when Camarasaurus and Brachiosaurus?
Camarasaurus is one of the most common sauropods in the Late Jurassic Morrison Formation localities in Colorado, Utah and Wyoming.
Lec 10: Derived charactes wth separate with the Sauropodamorpha from the Therapoda include?
Derived characters which separate the Sauropodamorpha from the Therapoda include: ▪relatively small skull (5% body length) ▪ deflected front end of lower jaw (downturned dentary) ▪elongate, lanceolate teeth with coarsely serrated crowns ▪at least ten neck vertebrae that form a very long neck ▪enormous thumb equipped with an enlarged claw ▪an elongate femur
Ch 10: understand the derived characters which split the Sauropodomorpha
Derived characters which separate the Sauropodomorpha from the Therapoda (the 2ndmajor group of the Saurischians) include: relatively small skull (5% body length) deflected front end of lower jaw (downturned dentary)elongate, lanceolate teeth with coarsely serrated crowns at least ten neck vertebrae that form a very long neck dorsal and caudal vertebrae added to the front and hind ends of the sacrum 1st digit (thumb) enlarged and equipped with a substantial claw a very large obturator foramen in the pubis an elongate femur compared to the lower leg bones (tibia and fibula)
Lec 9: How are dryosauurs and Camptosaurs the same? How are they different?
Dryosaurs- small to medium sized Iguanodontians found in Late Jurassic to Early Cretaceous rocks in North America, Europe, and Africa. Dryosaurs had a small head which was subtriangular in shape. The beak was small and squared off. Arms were so short that they must have been fully bipedal. Dryosaurs were made for running.
Lec 10: Be able to recognize and know the particulars about Massospondylus. Where? When? Nests and babies?
Eggs and nests are known for Mussasaurus (Argentina), and Massospondylus (South Africa, which you learned about in an activity from the textbook). Massospondylus, prosauropod embryo, of the earliest Jurassic http://www.democraticunderground.com/discuss/duboard.php?az=view_all&address=228x9859 Clutches are ~ 10 eggs, small by most dinosaur standards. Hatchlings are small. Adults are about 500-1000 x as large, implying fast growth rates. The unhatched, yet well-developed, embryos of Massospondylus did not have fully developed bones, so may have required parental care for the first part of their lives.
Lec 11: What were their footprints like? Where was their foot placement compared to the width of the body itself?
Even though their bodies are broad, trackways show that sauropod foot placement was not so far apart; their feet were aligned along the midline of the body
Ch 7: Understand the similarities and differences between the Ankylosauria and the Stegosauria
How were the ankylosauria dissimilar to stegosaurs: the wear marks on teeth in this group show that grinding did take place. likely that they had a long, flexible tongue because they had large hyoid bones (to which the tongue muscles would attach) had a wide secondary palate, which allowed them to chew and breathe at the same time deeply inset tooth rows point to well-developed cheeks to keep food from falling out of the mouth except for tooth design and placement, jaw structures point to reasonably efficient chewing Sauropelta, Nodosauridae: Enlarged acromial process on shoulder bone, often enlarged parascapular spines, narrow mouth at snour (probably more slective in what it ate), flaring hips and pillar like limbs. Ankylosaurus: Club at end of tail, triangular squamosal plates (on back of skull), wide mouth at snout (wasn't picky eater)
Lec 9: Know all the particulars of Iguanodon bernissartenis?
Iguanodon bernissartensis was talked about in Chapter 2 of the textbook. It is known from a collection of complete skeletons from deep in a coal mine in Belgium. It is Early Cretaceous in age, and averaged 8 m long, and 3.2 metric tons in weight. The body was heavily constructed, with long arms that allowed it to be semi-quadrupedal. The hands were large, and the thumb spike very large. The feet were also large. The head was elongate and subrectangular with a deep lower jaw with a rounded front, but a narrow beak on the upper jaw.
Lec 8: Ceraptosids General size? Collection locations? ow did all members of this clade move?
In general, the Centrosaurinae have shorter brow horns, a longer nose horn, and shorter frills. The Ceratopsinae have shorter nose horns, longer brow horns, and longer, taller frills. In both clades, the upper beaks are hooked, and brow and/or nasal horns are present. The skulls of certain forms also have bosses and hornlets in other areas. The head frills are well developed and at times very elaborate. In the figure at right, the artist has colored the bones of the skulls, comparing the size and shape of the various parts of the skull. These dinosaurs probably grew up fast. We have various growth stages for more than a few genera of this clade, and the juveniles show a lack of elaborate horns and frills compared to the adults. It is apparent that these features developed over time and show a remodeling of the bone involved. That type of remodeling of bone is also how mammals grow larger, and may imply some type of endothermy. If these features do not develop until the animal is approaching sexual maturity, it also points to the importance of those features in sexual selection.
Ch 10: know the general characteristics for all Saurischian dinosaurs
In this condition, the pubis bone points towards the front of the animal, down into the gut cavity. There are over a dozen (12) derived features which all Saurischians share; two of them are: Dorsal vertebrae has an extra hyposphene-hypantrum articulation (which is something involved with the "wings" on the sides of the vertebrae).Thumb (digit I of the hand) twists outwards.
Lec 8: General differences between the Psittacosaurids and the Neoceraptopsians?
In this group the upper beak is more hooked than it is in the Psittacosaurids. Neoceratopsians are more likely to be quadrupedal, especially the highly advanced forms of the Late Cretaceous in North America. The tails in this clade are proportionately shorter than in earlier, less derived forms. The front legs are somewhat shorter than the rear. The hands are five fingered, and all fingers and toes have tiny, individual hooves. The skulls are narrower towards the front than those in the Psittacosaurids.
Lec 8: How much do we know about all the different growth/life stage of Proteroceratops?
Members of this clade have been found in both Lower and Upper Cretaceous rock formations. The type species of this genus, P. andrewsi, is found in Upper Cretaceous rocks, and it is known from dozens of skulls and skeletons, most of which are complete, and which cover all ages from hatchlings to adults. This species lived in a desert environment, similar conditions to that which prevails today in that region of Mongolia. P. andrewsi had a very large head for the length of its body (8 ft), and it weighed ~ 380 lbs. The skull has an incipient nasal horn, and the frill on its head is broad and large. There are tall neural spines on the vertebrae of the tail, forming a shallow sail.
Ch 8.2: understand the connection between the horns and neck frills characteristic of the clade, and ceratopsian behavior in both intraspecific and interspecific dinosaur relationships
More recently we've begun to think that there was more to it than that, and that horns could have easily been used for intraspecific behavior such as display ritualized combat defense of territories establishment of social ordering (We know these were herd animals, for sure). In horned mammals, larger males have reproductive advantage over smaller males, as dominance is increased by structures that emphasize the size of the animal, horns, antlers, etc. Current thought is that the large nasal and brow horns in ceratopsians functioned primarily during territorial defense and in establishing dominance. The elaborate scallops and spikes along the frill margin in many of the more derived ceratopsians would help them recognize their own species among others. This would make these features useful for interspecific identification as well as to establish intraspecific dominance. Some dinosaurs exhibit evidence of this in that there are two distinct populations of adult frill and facial morphologies- both strong evidence of sexual dimorphism. Juveniles don't have much frill at all; those features don't develop until the animals attain 75% of their adult body mass.
Lec 7: General physical characteristics used to differentiate each of the three families within Ankylosauria - Ankylosauridae, Nodosauridae, Polecanthidae
Nodosauridae- ▪ long snouts, with downward curvature of front end of mandible ▪ well-muscled shoulders, with a large knob of bone on the shoulder blade (acromial process, which served as an attachment site for those muscles) ▪ flaring hips and pillar-like limbs (longer limb length than other ankylosaurs) ▪ many had tall spines at the shoulder (parascapular spines) ▪ known principally from North America and Europe with recent finds in Australia and Antarctica Ankylosauridae- All dinosaurs in this clade of Ankylosauria were well armored, but they had fewer tall spines along the body than many of the Nodosauridae. The tail in the Ankylosauridae ends in a massive, bony club which in some species had several paired knobs, or triangular spikes along its length.
Ch 7: Lmpw the characteristics of each of the families within the Ankylosauria, and be able to assign those characteristics, when presented, to the proper family, whether Nodosauridae or Ankylosauridae, or Polecanthids within the Ankylosauria
Nodosauridae: Long snouts Well-muscled shoulders, with a large knob of bone on the shoulder blade (acromial process, which served as an attachment site for those muscles) Flaring hips and pillar-like limbs Many had tall spines at the shoulder (parascapular spines) Known principally from North America and Europe with recent finds in Australia and Antarctica Ankylosauridae: All dinosaurs in the second clade of Ankylosauria were well armored, but they had fewer tall spines along the body than many of the Nodosauridae. The tail in the Ankylosauridae ends in a massive, bony club which in some species had several paired knobs, or triangular spikes along its length. Polacanthid: The Polacanthid Ankylosaurs have smaller osteoderms, lack the extra long parascapular spines of the Nodosauridae, and also lack the tail club which is found in all Ankylosauridae. Other paleontologists feel that the Polacanthids are a subfamily within the Nodosauridae.
Lec 9: Ouranosaurs, Age? Where found? Skeletal characters which set it apart? Be able to recognize skeleton/artist representation from lecure notes
Ouranosaurus nigerensis (8.3m long; 2.2 metric tons) is known from a complete skull and most of two skeletons. It was collected from the upper Elrhaz Formation in Niger, and is of Early Cretaceous age. http://www.dinosaur.pref.fukui.jp/dino/dic/Ouranosaurus.jpg The head is shallow with an elongate snout, and square beak. There is a low ridge on the midline of the head. It has especially tall neural spines on the vertebrae of the trunk, hips and tail, which form a very tall sail. The arms are long so it was probably semiquadrupedal. The hand is short, and has a small thumb spike.
Ch 8: know the major clades of dinosaurs within the Marginocephalia
Pachycephalosauria (thick-headed) Ceratopsia (horn-faced)
P: How did all members of this clade move (stance)? (Always bipedally)
Pachycephalosaurs came from bipedal ancestral stock, and continued as bipeds through the last of the clade.
P: Where found? Age? Character of head ornamentation?
Pachycephalosaurus wyomingensis has been collected from late Late Cretaceous age rocks in Montana, South Dakota, and Wyoming. It is known from a few skulls and a majority of a skeleton, the skulls ranging from juvenile to adult. This is the genus into which Dracorex hogwartsia and Stygimoloch spinifer were placed (by some) upon recognition that they were probably younger versions of P. wyomingensis. Both of those species are known from the same age rocks as P. wyomingensis, and at times in the same rock formation, but never in the same exact collection locality.
Ch 10: understand the current knowledge about the skeletal and soft tissue structure, movement, and lifestyles of the Sauropoda
SKULL tooth row not inset; no "cheeks" teeth w/simple crowns that were triangular, spatulate (Camarasaurus), or slender and pencil-like (Diplodocus) tend to be delicately built with large natural openings (fenestrae); this is probably to lighten the skull since it was positioned at the end of a very long neck external nares (nostrils) positioned not at the end of the snout, but further up, some as far as above the eyes. The positioning of the nares has gotten a lot of attention. Lightness with strength is emphasized in the long neck, which has a complex system of girders and air pockets, in some up to 60% of the neck volume was open air. An important part of this structure in some sauropods was the Y-shaped neural arches on the vertebrae. Within the Y would have been a nuchal ligament, a rope of connective tissue which connected down from the head and along the back of the animal to help support the long neck and head without the need for enlarged musculature. Many sauropods had elongated neural spines projecting dorsally from the neural arches; in these there was no "Y", and many had sideways projections (see the Brachiosaurus vertebrae figure in the first part of this chapter). Ligaments and ossified tendons would still have had a lot of bone for attachment points. Sometimes trackways would show a heel pad behind the claws of both the fore- and hind feet. Sauropod footprints are huge, not uncommonly 1 meter across! Even though their bodies are broad, trackways show that sauropod foot placement was not so far apart; their feet were aligned along the midline of the body, as you saw in the figure of the prints. No tail drag marks have ever been seen, so the tail must have been held out behind them (on some that is 15 m worth of tail!). This group has the smallest brain to body size of all the dinosaurs, but they were around for a long time, so whatever they were doing it worked, despite them not having much brain power. There is an open area in the sacrum area of the spine which is similar to that which is found in Stegosaurus. In the past, this open area was misinterpreted as having contained a "second brain" which would have helped in the movement/reaction time of the back part of these extra-large animals. It is now theorized to have been filled with Glycogen (such as birds have in a similar space in their sacrum). FEEDING Tooth form and wear (or lack thereof) indicate that sauropods nipped and stripped foliage, and delivered it largely unchewed down their elongate esophagus. Studies of sauropod skulls, jaw articulation, placement of teeth, and muscle attachments point towards a bite and swallow style of feeding. In the abdomen, the food would first enter the gizzard, filled with gastroliths. Contraction of the muscular walls of this organ would grind the food, before passing it back into the stomach chamber(s). Even with the forward projecting pubis "in the way", the gut must have been humongous. The stomach chamber(s) would have housed endosymbionts: bacteria that lived in the gut of the dinosaur that helped with the digestion of plant matter by fermentation. This process would have created a lot of methane as a by-product. High fiber vegetation would have had to be moved slowly through the system in order for these dinosaurs to have extracted the necessary nutrients. With their small heads, they must have eaten almost constantly to keep a steady supply of food going through their processing system. DEFENSE Size would have been the best deterrent as the Sauropods were between 50% and 300% larger than co-existing predators (remember the figure at the beginning of the chapter comparing them to a T. rex).
Lec 7: Know the following genera for which family group they are in, based on their distinguishing characteristics: Sauropelta, Ankylosaurus, Gargoyleosaurus, Pinacosaurus
Sauropelta edwardsorum (edwardsi) is the only known species of the genus. This genus lived earlier than any other Nodosaurid genus. Sauropelta has been found at several different Early Cretaceous localities in the western United States, but is most common in the Cloverly Formation (~115-110myo). In the Cloverly Formation, it shared living space with the early HadrosaurTenontosaurus. Although only medium sized for a Nodosaurid, Sauropelta weighed up to 1,500 kg, mostly due to its extensive armor, including some large spines. Sauropelta had enlarged parascapular spines, but also had spinous projections from the overlapping osteoderms on the dorsal side of the neck. Sauropelta had enlarged parascapular spines, but also had spinous projections from the overlapping osteoderms on the dorsal side of the neck. Osteoderms on the sides of the neck had sharp projections, becoming larger toward the shoulders (including the parascapular spine), and then reduced in size again along the length of the body. At the hips, these are flat plates which reduce in size moving towards the end of the extra-long tail. Sauropelta lived in wide floodplains around rivers that drained into the shallow inland sea to the north and east of the Wyoming and Montana localities in which it lived. Periodic floods would deposit fine, muddy sediment, and often trap and entomb animals living in the region. AnkylosauridaeThe characteristic features include a low, wide skull with remodeled surface or small pieces of armor fused to it, and a completely modified pelvis to accommodate a wide gut. This group has more than several genera ranging from the Early Late to Late-Late Cretaceous. Early Late forms include Cedarpelta from Utah,Crichtonsaurus from NE China, and Talarurus from Mongolia. Talarurus plicatospineus, at the typical length of 5 m, is considered the standard for the clade as a whole. http://museumvictoria.com.au/pages/8755/MM-talarurus-illustration-BIG.jpg Talarurus was first collected as an almost complete skeleton in 1948. Subsequent expeditions have recovered another skeleton, and 3 other specimens which are partials. It had a barrel-shaped body, and osteoderms and spines which are described as "pleated" or "furrowed". PolacanthiansGargoyleosaurus parkpinorum was 3 m long and weighed around 300 kg. It is from the Late Jurassic of Wyoming, probably from the Upper Morrison Formation. The first find of this polacanthid was a complete skull and an incomplete skeleton. Two other partial skeletons are known. The skeleton is shown in the figure above, with nodosauridae and ankylosauridae samples. This cast of the reconstructed skeleton is displayed in the Denver Museum of Nature and Science. The head is heavily armored, with small teeth at the front of the upper jaw. The body armor consists of thin, laterally projected spines along the sides of the dinosaur, and the dors
Lec 10: Prosauropods are what fraction of the Sauropodamorpha diversity? When did they live? Where did they live? What were their arms and feet like? How did they digest their food? Evidence for that?
Sauropodomorpha- Prosauropoda and Sauropoda •first of this clade were some of the first dinosaurs •they are found on every continent, although only sauropoda on Australia •very successful group with well over 100 different species • Sauropodamorpha are split 1/3 prosauropods, & 2/3 sauropods. Some of the larger forms of the Sauropodomorpha pushed the physiological limits which terrestrial animals could reach. Modifications to the skeletal elements, and soft tissues, would be a necessity to obtain such great sizes. The brain to body ratio within the Sauropodamorpha differed considerably, but all forms had a tendency towards smaller skull/brain size. Prosauropods- These basal sauropodomorpha ▪ appeared in the late Triassic, and were gone by the early Jurassic ▪ found on every continent except Australia ▪ in general, front limbs shorter than rear limbs ▪all limbs had 5 digits ▪ ½ moon-shaped thumb claw on front limbs; the actual function of the claw remains unknown Gastroliths have been found in association with both prosauropod and sauropod skeletons, plus it is thought that both probably utilized fermenting bacteria in their guts to aid in the digestion of their plant based diet
Ch 8.2: know the circumstances of the collection of Ceratopsian skeletons from bone beds, and what those collection localities imply for Ceratopsian behavior
Sexual selection is also thought to occur in the derived ceratopsians Centrosaurus and Chasmosaurus. It is very apparent that ceratopsians were social animals. There are an increasing number of ceratopsian "bone beds" (mass accumulations of single species of organisms). Bone beds are known for 9 different species of Ceratopsians.
Lec 11: Shunosaurus, Where? When? What is unusual about the tail in this genus?
Shunosaurus is of Middle Jurassic age and is from the Lower Xiashaximiao Formation, in Sichuan Province, in China. Shunosaurus was originally discovered in 1977 by paleontology students practicing their techniques in a road cut. This dinosaur was ~ 31 feet long and an unusual sauropod in that it had a small "club" on the end of its tail. Shunosaurus had a proportionately short neck for a sauropod. It makes up 90% of the specimens of dinosaurs of the fauna of the locality in which it was found
Lec 9: General characteristics of clade?
Skull- ▪ Head not greatly enlarged ▪ Beaks not hooked ▪ Eyes large ▪ Cheek teeth rows well developed Body- ▪ Neck S-curved ▪ Ossified tendons stiffen the trunk and tail ▪ Tail usually longer than shorter ▪ Four or five fingers; three or four toes Members of this clade can move either bipedally or quadrupedally. Arms and legs are flexed, and the legs are long, so they are good runners. Since there are no ribs attached to the lumbar vertebrae (unlike most reptiles, including most dinosaurs), the Ornithopoda are thought to have perhaps a muscular diaphragm as found in mammals.
Lec 11: Sauropoda - In general what was the head like? Teeth?
Skull- ▪ tooth row not inset; no "cheeks" ▪ teeth w/simple crowns that were triangular, spatulate (Camarasaurus), or slender and pencil-like (Diplodocus) see figure below ▪ tend to be delicately built with large natural openings (fenestrae); this is probably to lighten the skull since it was positioned at the end of a very long neck ▪ external nares (nostrils) positioned not at the end of the snout, but further up, some as far as above the eyes. Even if the openings are in the upper part of the skull, some paleontologists speculate that there were fleshy structures which caused the actual opening (nostril) to be in a different part of the skull than the openings in the skull itself.
Lec 8: Psittacosaurids - Age? Where found? General skeletal characteristics? How did they move? Diversity levels? Often found with what aid to digestion?
The Early Cretaceous Psittacosaurids were found in different areas of Northern and Central China, Mongolia, which is the country east-northeast of Xinjiang Province in China, and Siberia. Psittacosaurids had a broad head, small nostrils, no teeth on the front of the jaw, and a beak but which isn't hooked as much as is seen in more advanced ceratopsians. The sides of the skull often had projections (jugal bosses). They would have moved bipedally at speed, and quadrupedally when moving slowly, possibly when feeding. The arms were short with blunt claws on their three fingers. Members of this clade are frequently preserved with gastroliths. Long bristle fibers are known from several genera/species, positioned on the dorsal side of the tail, and perhaps further anteriorly along the back.
Lec 8: General characters of the Protoceratopsid clade?
The Protoceratopsids are based on the genus Protoceratops. In the cladogram above, the genera in this clade separated into the Protoceratopsidae and the Leptoceratopsidae families. Protoceratops has been known since the expedition to Mongolia made in 1922 by the crew from the American Museum of Natural History. Members of this clade have been found in both Lower and Upper Cretaceous rock formations. The type species of this genus, P. andrewsi, is found in Upper Cretaceous rocks, and it is known from dozens of skulls and skeletons, most of which are complete, and which cover all ages from hatchlings to adults. This species lived in a desert environment, similar conditions to that which prevails today in that region of Mongolia.
Ch 6: Know the characteristics which group the Therapoda together
Thyreophora are those Genasaurs in which there are parallel rows of keeled dermal armor scutes (or bony plates) on the back surface of the body. Thyreophorans are characterized by: parallel rows of special bones called osteoderms the osteoderms were embedded in their skin, running down the necks, backs, and tails
P: Know details about the best known species of Stegoceras, S. validum. Age? Where found? What type of fossil material do we have for this species?
The best known of the Stegoceras species is S. validum, which was ~ 7 ft long and weighed ~ 80 lb. It is larger than the species mentioned above that were first assigned to Stegoceras and later assigned elsewhere. We have enough skull domes preserved of this species that there is evidence of two distinctly different configurations of the same size domes. Not enough to be classified separately, but enough to be thought of as an expression of sexual dimorphism. Numerous skeletons have been collected of the type species, most from Dinosaur Park in Alberta, making it Late Cretaceous in age
Lec 10: Be able to recognize Plateosaurus and when and where it lived
The first known prosauropod, having been described from European specimens even before Sir Richard Owen coined the term "Dinosauria", is Plateosaurus. It is Late Triassic in age, and has at least 3 different European species, one which has been found at various localities across France, Germany, and Switzerland, and two known only from Southern Germany. This genus is known from numerous specimens of skulls & skeletons, of adults and juveniles.
P: Large gut and the character of their teeth probably means what?
The hands and feet of the Pachycephalosaurs were small, but their gut area was large. Because of their girth, it is thought that they perhaps had multi-chambered stomachs, and used fermentation as a way of digesting their diet of vegetation.
Ch 7: understand the placement of the Ankylosauria within the clade Thyreophora
The last chapter covered the basal Thyreophora, and the Stegosaurian Eurypoda. This chapter covers the Ankylosaurian Eurypoda. These dinosaurs were encased in bony plates and spines. Each plate and spine was embedded in skin, and interlocked with adjacent plates, forming a continuous shield across the neck, throat, back and tail. In some cases, they even covered the top of the head, cheeks, and eyelids.
P: The most derived of all the pachycephalosaurs is....
The most derived of all the Pachycephalosaurs is the genus which gives the clade its name.
Lec 8: For what purpose(s) the horns and neck frills?
The neck frill is tall, with the back rim extended into large, sideways-curving spikes. Small hornlets are positioned on the outside edge of the frill. This dinosaur is from the Late Cretaceous Lower Oldman Formation in Alberta.
P: Oldest possible Pachycephalosaur (if it is a Pachy) is how old? From where? What characters does it have that make it a Pachy?
The oldest possible pachycephalosaur is Stenopelix valdensis a 4.5 ft long, relatively lightly built dinosaur from the Early Cretaceous. It is from Central Germany, and is known from the majority of a skeleton
P: Do Pachycephalosaurs undergo ontogenetic change during their lives? What is the connection of this phenomena with an apparent loss of diversity in the group?
This clade does not have the diversity of form like that seen in the Ceratopsians. In fact, more than a few of the Pachycephalosaurs, which were first assigned to their own genus, were with further review considered by some to be juvenile and/or subadult growth stages of species assigned to other genera. Your text has a video which covers this as concerns Dracorex, Stygimoloch, and Pachycephalosaurus. There appears to have been two main groups of Pachycephalosaurs, less derived forms which are predominantly Asian, and more derived forms which lived in North America closer to the time of the great extinction.
Pachycephalosauria: Age range and geographic locations of this clade?
This clade includes small to large dinosaurs from the Cretaceous of the Northern Hemisphere
P: Why are Dracores and Stygimoloch thought by many to all belong to the genus/species Pachycephalosauruswyomingensis
This is the genus into which Dracorex hogwartsia and Stygimoloch spinifer were placed (by some) upon recognition that they were probably younger versions of P. wyomingensis. Both of those species are known from the same age rocks as P. wyomingensis, and at times in the same rock formation, but never in the same exact collection locality.
Ch 6: understand the mechanics of chewing, and the skeletal elements involved in chewing
The primitive tetrapod condition is for the jaw joint to function like a pair of scissors because the jaw joint is at the same level as the tooth row. In Ornithischians, the jaw joint is below the level of the tooth row, and so the jaws function more like a tool where the jaws close along their entire length, simultaneously, like in the pipe wrench in this figure. In many dinosaurs, including all Ornithischians, teeth didn't actually do a cropping function. That function was done by a beak, or rhamphotheca. This feature is made out of keratin, a protein-based substance that makes up horns, nails, hooves, and claws
Ch 7: Understand the breadth of the information known about the dinosaurs within the Ankylosauria in regards to their size, diet, where they located, and how they are found fossilized in Asia and North America, and their feeding patterns, reproduction, and ability to defend theirselves
Those in North America are usually fragmentary, often upside down, sometimes in rocks which were deposited in a shoreline environment, sometimes in marine rocks. This was probably due to their bloated carcasses being carried out with the tide, and the heavy, plated upper side flipping to the bottom. Ankylosaurs are generally found as individual skeletons, whole or in part. Only one instance of a bone bed (numerous individuals) is known, so they may have been solitary animals, they apparently did not enjoy company. Two major clades: Nodosauridae (nodo=knot; referring to their round osteoderms Ankylosauridae
P: Head butting? Vision?
The thickness of the skull dome in this genus is typically ~ 3 inches. CT scans of the skulls of the type species points to them being able to withstand head butting without significant risk of injury. It is suggested that Stegoceras had good vision, with some stereoscopic capability
Lec 8: In general, the Centrosaurinae have...
There are at least two species of Centrosaurus (= Styracosaurus), one from Alberta, and one from Montana. Styracosaurus ovatus is from the Upper Two Medicine formation in Montana, was 17 ft long and about 2 metric tons in weight. These dinosaurs had pronounced nose horns, small bosses above their eyes, and numerous small and elongate spikes on the perimeter of their frill.
Ch 10: know certain facts about and the derived characters of the Prosauropoda
These basal sauropodomorpha: appeared in the late Triassic, and were gone by the early Jurassic evolution has a parallel history with the rising dominance of the Gymnosperm seed plants over spore-bearing plants found on every continent except Australia in general, front limbs shorter than rear limbs all limbs had 5 digits ½ moon-shaped thumb claw on front limbs; the actual function of the claw remains unknown
Lec 8: What is the dental battery like in this group?
These dinosaurs have their molar teeth developed into a dental battery which contain hundreds of stacked teeth. They had the ability to chew their food really well.
Lec 10: Age, location, and what is unusual about Mussauruspatagonicus?
Various genera of prosauropods have been described from the Late Triassic of Argentina. The two best known due to partial to complete skulls, and numerous skeletons a mix of adults and juveniles having been found, are Mussaurus patagonicus, from southern Argentina, and Riojasaurus incertus, from Northern Argentina. M. patagonicus has more juvenile material, thus the adult size is not yet known for certain. The proportionately longer arms point towards quadrupedal stance, at least when young. Here is a drawing of the skull, with scale bar. The skull is shorter and deeper than seen in most adult prosauropods, and the eye orbit is HUGE!
Lec 11: Basal form of Vulcanodon. Where? When? Size?
Vulcanodon is an Early Jurassic basal sauropod found in the southern African nation of Zimbabwe. There is only one species, the type, V. karibaensis. This species is known from the back ½ of a skeleton plus the front limbs, only. The trunk & neck vertebrae, and the skull, are missing. Structurally, Vulcanodon is a true sauropod, but it is much smaller than others, at ~ 20 feet in length.
Ch 9: understand the fossil evidence for the Ornithopoda
We have enough fossil material that we know a lot of information about the Ornithopoda. The first found and described, by Mantell (with help from Sir Richard Owen) in 1842, was Iguanodon. We know Hadrosaurids (duckbills) from single bones, and bone beds. We have ossified tendons,and skin impressions of this group, along with small bones that are usually lost before fossilization. These small bones could be those of the inner ear, or the bones of the sclerotic ring (around the eye), or perhaps those of the throat (hyoid bones). We have hadrosaurid eggs, and all growth stages, from hatchling to adolescent to adult. Their footprints and trackways have been found all over the world. In 2008, a mummified hadrosaur, named Leonardo, went on display at the Houston Museum of Natural Science.
Lec 8: What is different/characteristic about Zuniceratops?
Zuniceratops is known from several partial skulls and skeletons. At 6.5 ft long and 390 lbs, it is about the size of Protoceratops, but its skull features are more advanced. The head is long with no nasal horn, but the brow horns are large, and its frill taller than any other protoceratopsid. As you may guess from the name, Zuniceratops was found in Upper Cretaceous rocks at Moreno Hill, in New Mexico (where the Zuni Native Americans live)
Lec 11: What are nuchal ligaments, and what use are they?
a rope of connective tissue which connected down from the head and along the back of the animal to help support the long neck and head without the need for enlarged musculature.
Lec 8: be able to match the skulls of the following up with their names: Albertoceratops, Styracosarus, Pachyrhinosaurus, Chasmosaurus, Triceratops
alberto - weird 2 hook hornlets. chasmo - flat frill on top.
Ch 10: understand the current knowledge of Prosauropoda lifestyle
he teeth themselves are generally separated & leaf-shaped, with few grinding marks There is some question as to whether these dinosaurs were true herbivores or not, but there is a good chance that their diet was mostly herbivore, with an occasional helping of meat when they could get ahold of it. The actual grinding of their food was done by gastroliths (gizzard stones), which have been found in close association with fossil skeletons. Both prosauropods and sauropods are often found with polished gastroliths. They are also thought to have had stomach fermentation because of their barrel-shaped torso (although not as proportionately big as in ankylosaurs). Length of limbs and a short torso in the prosauropods points towards primary bipedality, as in Plateosaurus.
Lec 8: How do we think the Ceratopsian lineage got from eastern Asia to N America?
land bridge
Be able to recognize Alamosaurus, and Saltasaurus, and know their age and where found?
locality in Texas, in the uppermost layers of the Cretaceous which were deposited very close to the end of the Mesozoic Era. This would make it one of the last dinosaurs to have existed on Earth. Salt - The only species, S. loricus, is known from Late Cretaceous localities in northwest Argentina, and Uruguay.
have a detailed understanding of the Stegosauria including: physical characteristics, morphology of skull and teeth, brain to body proportions and braincase data
medium-sized dinosaurs 3-9 m in length, weighing 300-1500 kg osteoderms were developed into spines and plates body profiles sloped strongly forward and down hindlimbs substantially longer than forelimbs all toes had broad hooves relatively uncommon but had global distribution on mostly northern continents during the Jurassic
Ch 7: Know the general characteristics of the dinosaurs within the Ankylosauria
mid-size dinosaur, rarely more than 5 m in length Ankylosaurus itself was the largest at up to 9 m limbs different lengths, with hind limb as much as 150% the length of the front global distribution, predominantly from North America and Asia, but also Europe, Australia, South America, and Antarctica Group reached peak diversity in Cretaceous
Ch 9: understand the following features of the Ornithopods: movement, fromt limbs, skull teeth & gut, senses
movement: functioned as bipeds and quadrupeds. The smaller the dinosaur the more likely it spent more time as a biped, though they were probably quadrupedal when moving slowly, as during feeding. The larger probably spent more time as a quadruped, except when speed was necessary. The vertebral column would have been too rigid for quadrupedal galloping, plus the front limbs had limited movement against the ribcage and sternum. It makes more sense for the dinosaurs to have held the front limbs up near the sides of the body while running. tail was long, muscular, strengthened by ossified tendons and held at, or near, horizontal. in general, the powerful hind limbs were as long as the length of the front limbs, ranging up to greater than 2x the length speed of movement varied by size and build- large hadrosaurs sustained run 15-20 km/h Short sprint ~ 50km/h smaller, more agile, maximum of ~60 km/h Front limbs: A basal Ornithopod, Heterodontosaurus, had powerful forelimbs and clawed hands, to grab vegetation or dig up roots and tubers.Somewhat less powerful forelimbs are the norm in most Euornithopods, probably only using their forelimbs to bring branches closer to their toothed beak, and for walking. Iguantodontids had specialized fingers and hands, indicating multiple functions. first digit conical and sharply pointed Defensive weapon? For breaking into seeds? digits II, III & IV tipped with hooves, and weight-bearing outermost finger, digit V, was highly flexible, and could bend across the palm, a grasping, opposable, pinkie. Skull: Remember that as genasaurs, ornithipods have a mouth with a beak in front for cropping vegetation diastema (gap between front and back teeth) group of cheek teeth for shearing which are deeply inset (indicating large fleshy cheeks) large, well-developed coronoid process for serious chewing. Teeth: Chewing in Ornithopods reached its most refined state in the hadrosaurs, which had their cheek teeth in a tightly packed dental battery. Ornithopods also had large guts for thorough digestion of the well-chewed vegetation. This is especially true of the iguanadontians (including hadrosaurs). Ornithopods had a larger brain to body size ratio than other ornithischians. Many had enlarged lobes in their brain for sight, smell and hearing, probably for protection against predation more than any other reason. They are also considered very social animals, and that could also make a larger brain necessary.
Even though they are in the Titanosauria, are all of them in that clade huge?
no
Lec 8: What does the narrow, hooked beak do for them/mean about their diet?
probably allowed them to be very selective about what type of plants they consumed.