[9] In 1990 the Russian paleontologist Sergei Mikhailovich Kurzanov referred additional material from Hermiin Tsav to P. kozlowskii. These individuals were considered as females. [60], David J. Button and Lindsay E. Zanno in 2019 performed a large phylogenetic analysis based on skull biomechanical charactersprovided by 160 Mesozoic dinosaur speciesto analyze the multiple emergences of herbivory among non-avian dinosaurs. [11], Fastovsky in 1997 examined the geology at Tugriken Shireh providing insights into the taphonomy of Protoceratops. Based on these components, the paleoenvironments of the Djadokhta Formation are interpreted as having a hot, semiarid climate with large dune fields/sand dunes and several short-lived water bodies, similar to the modern Gobi Desert. The first metatarsal and toe were the smallest, while the other elements were of similar shape and length. Protoceratops Protoceratops ("Before the horned-faces") is well known from numerous skeletons, ranging from young animals to adults. Frambenen var ungefr 30% kortare n bakbenen, [ 3] vilket . Found as fossils in deposits from the Late Cretaceous Period (about 100 million to 65.5 million years ago) of eastern Asia and North America, Oviraptor was about 1.8 metres (6 feet) long and walked on two long, well-developed hind limbs. [126], Mayor in 2001 and 2011 defended the hypothesis of Protoceratops as an influence over the griffin by citing that some other Greek histories about mythological creatures may have had their origins at the hands of fossil findings made by ancient people. Protoceratops was a herbivore, living in the late Cretaceous of China and Mongolia. Lastly, he restored the course of the fight with the Protoceratops power-slamming the Velociraptor, which used its feet claws to damage the throat and belly regions and its hand claws to grasp the herbivore's head. The phylogenetic analysis performed by the team recovered both protoceratopsids as sister taxa, indicating that Bagaceratops and Protoceratops were anatomically and systematically related. Given the dry/harsh paleoenvironmental conditions of units like the Djadokhta Formation, medium to large-sized dinosaur carcasses may have been an important source of nutrition for small animals. The most intimidating parts of the otherwise gentle Protoceratops were its teeth, beak and jaws, which this dinosaur used to clip, tear and chew the tough vegetation of its central Asian habitat. Additionally, Longrich suggested that a backward burrowing could explain the preservation of some specimens pointing forward with curved tails. Back in Beijing, the skull Shackelford had found was sent back to the American Museum of Natural History for further study, after which Osborn reached out to Andrews and team via cable, notifying them about the importance of the specimen. Dinosaurios. It is one of the oldest species of stegosaurs known and would have resembled Kentrosaurus in appearance. [69], Gregory and Mook in 1925 suggested that Protoceratops was partially aquatic because of its large feetbeing larger than the handsand the very long neural spines found in the caudal (tail) vertebrae. They interpreted the interaction as the Protoceratops being grasped and dispatched with kicks delivered by the low-lying Velociraptor. Dinosaurs Tour expondr Triceratops, Tiranosaurios, Protoceratops, Parasaurolofus, Estegosaurios, Espinosaurio, Diplodocus y el famoso Tiranosaurio Rex a tamao real, entre otros. Protoceratops is one of the most common dinosaurs from its habitat and region which, along with its size, has given it the nickname "Sheep of the Cretaceous". A dinosaur habitat right next to rivers are floodplains. [99] and its dinosaur paleofauna is composed of alvarezsaurids Kol and Shuvuuia;[104][105] ankylosaurid Minotaurasaurus;[106] birds Apsaravis and Gobipteryx;[107][108] dromaeosaurid Tsaagan;[109] oviraptorids Citipati and Khaan;[110] troodontids Almas and Byronosaurus;[111][112] and a new, unnamed protoceratopsid closely related to Protoceratops. The angular was located below the two latter bones and behind the dentary. Both parietals were coossified (fused), creating a long ridge on the center of the frill. [3] In the same year, Granger and William K. Gregory formally described the new genus and species Protoceratops andrewsi based on the holotype skull. Such placement of the muscles may have helped to anchor the lower jaws, useful for feeding. [78], In 2020 nevertheless, Andrew C. Knapp and team conducted morphometric analyses of a large sample of P. andrewsi specimens, primarily confluding that the neck frill of Protoceratops has no indicators or evidence for being sexually dimorphic. It belonged to a group of dinosaurs called the Cerapoda. Such skull traits were regarded as marked [[Genetic variability [53], In 2019 Czepiski analyzed a vast majority of referred specimens to the ceratopsians Bagaceratops and Breviceratops, and concluded that most were in fact specimens of the former. [22] The authors Brenda J. Chinnery and Jhon R. Horner in 2007 during their description of Cerasinops stated that Bainoceratops, along with other dubious genera, was determined to be either a variant or immature specimen of other genera. The Velociraptor has its right leg pinned under the Protoceratops body with its left sickle claw oriented into the throat region. [70], In 2008, based on the occurrence of some Protoceratops specimens in fluvial (river-deposited) sediments from the Djadokhta Formation and heterocoelous (vertebral centra that are saddle-shaped at both ends) caudal vertebrae of protoceratopsids, Tereshchenko concluded that the elevated caudal spines are a swimming adaptation. 1. andrewsi (Granger and Gregory, 1923) juveniles in situ from from MPC-D 100/530. In both nests, the babies' heads are oriented in the same direction, facing away from the ancient prevailing winds. Kosmoceratops is a dinosaur that was discovered in Utah in the United States. Unlike dentary and maxillary teeth, the premaxillary dentition was devoid of denticles, having a relatively smooth surface. They identified Protoceratops as an ornithischian dinosaur closely related to ceratopsians representing a possible common ancestor between ankylosaurs and ceratopsians. Such lineage was suggested to have started from the primitive ceratopsian Psittacosaurus. You would be forgiven for having never heard of it, not many have. On September 21, the expedition returned to Beijing, and even though it was set up to look for remains of human ancestors, the team collected numerous dinosaur fossils and thus provided insights into the rich fossil record of Asia. The neural arch and spine of the axis were notably larger than the atlas itself and any other cervical. The team also find that the growth rate of the femur increased at the subadult stage, suggesting changes in bone proportions, such as the elongation of the hindlimbs. They indicated that sexual dimorphism in this population was marked by a prominent nasal horn in malestrait also noted by other authorsrelative wider nostrils in females, and a wider neck frill in males. He considered unlikely such interpretation based on the relative fragility of some frill bones and the large individual variation, which may have affected the development of those muscles. Several of the embryos were associated with a black to white halo (circumference). Maryanska and Osmolska also emphasized that some early members of the Ceratopsidae reflect a much older evolutionary history. Most of the individuals within the nest had nearly the same age, size and growth, suggesting that they belonged to a single nest, rather than an aggregate of individuals. The specific name, kozlowskii, is in tribute to the Polish paleontologist Roman Kozowski. He concluded that the prominent displacement of pectoral elements and right forelimb was caused by an external force that tried to tear them out. The caudal vertebrae decreased in size progressively towards the end and had very elongated neural spines in the mid-series, forming a sail-like structure. [14], Protoceratopsid remains were recovered in the 1970s from the Khulsan locality of the Barun Goyot Formation, Mongolia, during the work of several Polish-Mongolian paleontological expeditions. According to Tereschenko, Bagaceratops was fully aquatic while Protoceratops was only partially aquatic. Story. The Gobi is now a desert. 1.4 (17 votes) Chialingosaurus kuani was a stegosaurian that lived 160 million years ago in China. The surfaces around the epijugal were coarse, indicating that it was covered by a horny sheath. The anterior facet of the atlas centrum was highly concave for the articulation of the occipital condyle of the skull. Given that the Velociraptor is relatively complete, Carpenter suggested that it may have been completely or partially buried by sand. This new species was based on the Khulsan material, mostly consisting of juvenile skull specimens. Norell and team performed histological examinations to its chemical composition, finding traces of proteinaceous eggshells, and when compared to other sauropsids the team concluded that they were not biomineralized in life and thus soft-shelled. The atlas was the smallest cervical and consisted mainly of the centrum because the neural arch (upper, and pointy vertebral region) was a thin, narrow bar of bone that extended upwards and backwards to the base of the axis neural spinespine. It was believed that the discovery of a small, herbivorous dinosaur named Protoceratops was the inspiration for the creation of the iconic griffin, a belief challenged in 2016 by paleontologist Mark Witton. Schmitz and Motani separated ecological and phylogenetic factors and by examining 164 living species and noticed that eye measurements are quite accurate when inferring diurnality, cathemerality, or nocturnality in extinct tetrapods. Protoceratops Shared its Habitat with Oviraptor. The dentary (teeth-bearing bone) was robust, deep, slightly recurved, and fused to the angular and surangular. [79], In 1989, Walter P. Coombs concluded that crocodilians, ratite and megapode birds were suitable modern analogs for dinosaur nesting behavior. [118], In 1993 Jerzykiewiczz suggested that many articulated Protoceratops specimens died in the process of trying to free themselves from massive sand bodies that trapped them during sandstorms events and were not transported by environmental factors. The palpebral (small spur-like bone) joined the prefrontal over the front of the orbit (eye socket). Later in 1923, W. K. Gregory and Walter Granger described the newly found species. Coahuilaceratops (meaning "Coahuila horn face") is a genus of ceratopsian dinosaur which lived in what is now Mexico. [35], In 2010 Nick Longrich examined the relatively large orbital ratio and sclerotic ring of Protoceratops, which he suggested as evidence for a nocturnal lifestyle. While Andy and his colleagues were able to show that the frill of Protoceratops likely evolved as a result of social behaviour between members of the species as opposed to, for example, defence, it is difficult to be conclusive that . It had a sharp end and rough texture, which reflects that a rhamphotheca (horny beak) was present. The hindlimbs were longer than the forelimbs. Protoceratops was a predecessor of the more familiar horned dinosaurs such as Triceratops. The AMNH is the best place to see it in the Americas, with a tableaux of a couple at a nesting sight and a rather famous skull growth series along the wall next to it. Protoceratops are dinosaurs confirmed to appear in Additional Creatures: Endemics. ", "A new leptoceratopsid dinosaur from Maastrichtian-aged deposits of the Sustut Basin, northern British Columbia, Canada", "Neural Spine Elongation in Dinosaurs: Sailbacks or Buffalo-Backs? [11], Stephan N. F. Spiekman and colleagues reported a partial P. andrewsi skull (RGM 818207) in the collections of the Naturalis Biodiversity Center, Netherlands in 2015. (Image credit: CC-BY-SA 4.0) Adorable sheep-sized dinosaurs probably evolved their fancy neck frills to attract mates or show . Weighing up to 100 poundsabout the size of a wolf Velociraptors likely hunted solo as they roamed across central and eastern Asia in the late Cretaceous . They were characterized by a proportionally large skull, short and stiff neck, and neck frill. The femur (thighbone) was robust and had a rather rounded and pronounced greater trochanter, which was slightly recurved into the inner sides. As a last effort, the Protoceratops bit the right hand of the predator and trapped it beneath its own weight, causing the eventual death and desiccation of the Velociraptor. The humerus (upper arm bone) was large and slender, and at the lower part it meet with both radius and ulna. The neck frill specifically, underwent a dramatic change from a small, flat, and almost rounded structure in juveniles to a large, fan-like one in fully mature Protoceratops individuals. [12] Gregory M. Erickson and team in 2017 reported an embryo-bearing egg clutch (MPC-D 100/1021) of Protoceratops from the also fossiliferous Ukhaa Tolgod locality, discovered during paleontological expeditions of the American Museum of Natural History and Mongolian Academy of Sciences. This low-browsing method would have allowed to feed on foliage and fruits within range, and large basal ceratopsians may have consumed tougher seeds or plant material not available to smaller basal ceratopsians. The Velociraptor has its right hand trapped within the jaws of the Protoceratops and the left one grasping the Protoceratops skull. As the name implies, they represent elongated dinosaur eggs, including some of referred ones to Protoceratops. After emerging from the eggs, larvae would have fed on the carcass prior to pupating. [23], As part of the Third Central Asiatic Expedition of 1923, Andrews and team discovered the holotype specimen of Oviraptor in association with some of the first known fossilized dinosaur eggs (nest AMNH 6508), in the Djadokhta Formation. As some individuals are closely appressed along the well-defined margin of the nest, it may have had a circular or semi-circular shapeas previously hypothetizedwith a diameter of 70cm (700mm). The fact that the individuals likely spend some time in the nest after hatching for growth suggests that Protoceratops parents might have cared for their young at nests during at least the early stages of life. Este grupo de saurpsidos apareci hace 231 millones de aos durante el perodo Trisico, aunque su origen y su diversificacin es . The hindlimbs of Protoceratops were rather long, with a slighter longer tibia (lower leg bone) than femur (thigh bone). [31], In 2018 Tereshchenko examined and described several articulated cervical vertebrae of P. andrewsi and reported the presence of two abnormally fused vertebrae (specimen PIN 3143/9). The last openings of the skull were two parietal fenestrae (holes in the frill). On the other hand P. hellenikorhinus had a total skull length of about 70cm (700mm). |intraspecific variation]] within Protoceratops, and they differ from other populations across the Djadokhta Formation (like Tugriken Shireh), being unique to the Udyn Sayr region. The main gait of Protoceratops was probably trot-like mostly using its hindlimbs and it is unlikely to have used an asymmetric gait. Protoceratops is the one dinosaur that every fossil hunting expedition finds in Mongolia. Protoceratops was discovered in 1922 . (Cretaceous, Campanian), Mongolia", "Insect Trace Fossils Associated with Protoceratops Carcasses in the Djadokhta Formation (Upper Cretaceous), Mongolia: Forensic Entomology in the Upper Cretaceous", "Trace fossils on dinosaur bones from Upper Cretaceous eolian deposits in Mongolia: Taphonomic interpretation of paleoecosystems in ancient desert environments", "Trace fossils on dinosaur skeletons from the Upper Cretaceous of Gobi desert, Mongolia", "Why Protoceratops almost certainly wasn't the inspiration for the griffin legend", Footage from the Third Central Asiatic Expedition, https://en.wikipedia.org/w/index.php?title=Protoceratops&oldid=1139818722, This page was last edited on 17 February 2023, at 01:55. [67] In 2010 Alexander Kuznetsov and Tereshchenko analyzed several vertebrae series of Protoceratops in order to estimate overall mobility, and concluded that Protoceratops had greater lateral mobility in the presacral (pre-hip) vertebrae series and reduced vertical mobility in the cervical (neck) region. The rear of the skull gave form to a pronounced neck frill (also known as "parietal frill") mostly composed of the parietal and squamosal bones. ", "Adaptive Features of Protoceratopsids (Ornithischia: Neoceratopsia)", "The first ceratopsian dinosaur from South Korea", "Sexual Dimorphism in the Postcranial Skeleton of Protoceratopsids (Neoceratopsia, Protoceratopsidae) from Mongolia", "Males Resemble Females: Re-Evaluating Sexual Dimorphism in Protoceratops andrewsi (Neoceratopsia, Protoceratopsidae)", "On Polymorphism of Protoceratops andrewsi Granger et Gregory, 1923 (Protoceratopidae, Neoceratopsia)", "Three-dimensional geometric morphometric analysis of the skull of Protoceratops andrewsi supports a socio-sexual signalling role for the ceratopsian frill", "Evidence of predatory behavior by carnivorous dinosaurs", "Evolution of vision and hearing modalities in theropod dinosaurs", 10.1671/0272-4634(2008)28[432:ANSOVD]2.0.CO;2, "A new dromaeosaurid (Dinosauria: Theropoda) from the Upper Cretaceous Wulansuhai Formation of Inner Mongolia, China", "A new oviraptorid from the Upper Cretaceous of Nei Mongol,China, and its stratigraphic implications", "A monodactyl nonavian dinosaur and the complex evolution of the alvarezsauroid hand", "A new species of the ankylosaurid dinosaur Pinacosaurus from the Late Cretaceous of Inner Mongolia (P.R. These areas of land are flat spaces that easily fill up with water when the rivers overflow and are dry when they don't. They're made of rocks, soil, and sand deposited by the river's flooding. The habitat seems to have been quite dry . In the Late Cretaceous, about 100 million years ago, the ceratopsians began to diversify in North America and in Asia. [77], In 2016 Hone and colleagues analyzed 37 skulls of P. andrewsi, finding that the neck frill of Protoceratops (in both length and width) underwent positive allometry during ontongeny, that is, a faster growth/development of this region than the rest of the animal. [97] Dominant sediments at Djadokhta include dominant reddish-orange and pale orange to light gray, medium to fine-grained sands and sandstones, caliche, and sparse fluvial (river-deposited) processes. The maxillary teeth of ceratopsians were usually packed into a dental battery that formed vertical shearing blades which probably chopped the leaves. They had a short but powerful tail and walked on four thick legs weighing up to 11,000 kg (24,250 pounds) and could reach up to 9m (30 feet) in length and 3m (10 feet) in height. [5][44][45], The vertebral column of Protoceratops had 9 cervical (neck), 12 dorsal (back), 8 sacral (pelvic) and over 40 caudal (tail) vertebrae. [121], In 2010 the paleontologists Yukihide Matsumoto and Mototaka Saneyoshi reported multiple borings and bite traces on joint areas of articulated Bagaceratops and Protoceratops specimens from the Tugriken Shireh locality of the Djadokhta Formation and Hermiin Tsav locality of the Barun Goyot Formation, respectively. Handa and team in addition found variation across this Udyn Sayr sample and classified them in three groups. [26], However, also during 1994, Norell and colleagues reported and briefly described a fossilized theropod embryo inside an egg (MPC-D 100/971) from the Djadokhta Formation. Protoceratops is a special dinosaur because they had really large eyes. At least 8 body fossils of Protoceratops present active teeth marks, which were interpreted as feeding traces. One specimen (MPC-D 100/551B) was shown to present skull traits that are intermediate between Bagaceratops rozhdestvenskyi (which is native to adjacent Bayan Mandahu and Barun Goyot) and P. andrewsi. The Wild Past Protoceratops w/ Nest with the Safari Ltd. Feathered Dinosaurs Toob version. Diabloceratops (/ d a b l o s r t p s / dy-AB-loh-SERR--tops) is an extinct genus of centrosaurine ceratopsian dinosaur that lived approximately 81.4-81 million years ago during the latter part of the Cretaceous Period in what is now Utah, in the United States. It lived in the Cretaceous period and inhabited Asia. This genus was based on a few dorsal (back) vertebrae that were stated to differ from those of Protoceratops. [13], In 2016 Meguru Takeuchi and team reported numerous fossilized feeding traces preserved on skeletons of Protoceratops from the Bayn Dzak, Tugriken Shireh, and Udyn Sayr localities, and also from other dinosaurs. [81], In 2011 the first authentic nest of Protoceratops (MPC-D 100/530) from the Tugriken Shireh locality was described by David E. Fastovsky and team. Like its larger and geologically younger relative Triceratops, this herbivore also had a bony . (plus 4 other paragraphs) Animal Characteristics: Habitat: Desert; Location: Asia; Era: Cretaceous Minimum happiness needed for chance of breeding: 95. They found at least three types of feeding traces on this individual; nearly circular boringswhich they found instead to correlate best with feeding traces made by dermestid beetlesof 0.61cm (6.010.0mm) in diameter; semicircular shaped notches at the edge of bones; and destruction of articular surfaces, mostly at the joints of the limbs. [15] Though Breviceratops has been regarded as a synonym and juvenile stage of Bagaceratops,[16][17] ukasz Czepiski in 2019 concluded that the former has enough anatomical differences to be considered as a separate taxon. Coahuilaceratops fossils have been recovered from strata of the Late Cretaceous Period (Campanian), around 72 Ma (million years ago). Knapp and team noted that results of the frill indicate that this structure had a major role in signaling within the species, consistent with selection of potential mates with quality ornamentation and hence reproductive success, or dominance signaling. Protoceratops (/protosrtps/; lit. Second group had a fairly rounded posterior border of the squamosal, and a long and well-developed bony ridge on the posterior border of the parietal bone. Protoceratops belonged to the group of Ceratopsians (Ceratopians) 5. . Later members, including ceratopsids like Centrosaurus and Triceratops, became very large quadrupeds and . This feeding method was likely more efficient in protoceratopsids as the enamel surface of Protoceratops was coarsely-textured and the tips of the micro-serrations developed on the basis of the teeth, probably helping to crumble vegetation. The specific name, andrewsi, is in honor of Andrews for his prominent leadership during the expeditions. The co-authors also agreed with Osborn in that Asia, if more explored, could solve many major evolutionary gaps in the fossil record. P. andrewsi bore two small, peg to spike-like teeth that were located on the underside of each premaxilla. Protoceratopsidae is a family of basal (primitive) ceratopsians from the Late Cretaceous period. After burial, either Protoceratops herd or scavengers tore off the buried Protoceratops to the left and backwards, making both predator and prey to be slightly separated. Protoceratops c dim xp np ln c, c th phc v nh l tm bo v c, ni duy tr cc c quai hm, e da cc loi khc, hoc t hp ca cc chc nng ny. Based on comparisons with other ornithischian dinosaurs such as Maiasaura and Orodromeusknown from more complete nestsThulborn concluded that most depictions of Protoceratops nests were based on incompletely preserved clutches and mostly on type A eggs, which were more likely to have been laid by an ornithopod. "It took up about a quarter of its whole body length, which is an unbelievably big skull," says Barrett. What kind of habitat did Protoceratops live in? Most of them had differences in the same exact vertebra, such as the shape and proportions of the vertebral centra and orientation of neural arches. changes in the late part of the Campanian stage. hellenikorhinus. On the underside of the caudal vertebrae a series of chevrons were attached, giving form to the lower part of the tail. 'first horned face') is a genus of small protoceratopsid dinosaurs that lived in Asia during the Late Cretaceous, around 75 to 71 million years ago.The genus Protoceratops includes two species: P. andrewsi and the larger P. hellenikorhinus.The former was described in 1923 with fossils from the Mongolian Djadokhta Formation, and the . The fusion of the vertebrae was likely a product of disease or external damage. It has been examined and studied by numerous researchers and paleontologists, debating on how the animals got buried and preserved altogether. The white arrow indicates a broken rib, and the black arrows point to pterosaur bones preserved inside the dinosaur's . The axial neural spine was broad and backwards developed being slightly connected to that of the third cervical. [39], Longrich in 2010 proposed that Protoceratops may have used its hindlimbs to dig burrows or take shelter under bushes and/or scrapes in order to escape the hottest temperatures of the day. [66], Upon the analysis of the forelimbs of several ceratopsians, Phil Senter in 2007 suggested that the hands of Protoceratops could reach the ground when the hindlimbs were upright, and the overall forelimb morphology and range of motion may reflect that it was at least a facultative (optional) quadruped. He also indicated that the anterior caudals were devoid of high neural spines and had increased mobilitya mobility that stars to decrease towards the high neural spines, which suggest that the tail could be largely raised from its base. Reported traces were identified as pits, notches, borings, and channels across the skeletons, most notably at limb joint areas. The tail may have been related with structures like the frill for displaying behavior. The team of the third expedition arrived in Beijing in 1921 for the final preparations and started working in the field in 1922. They interpreted the damaged areas in the Protoceratops specimen as product of active feeding by burrowing arthropods, most likely insects. Since Protoceratops fossils are only found in the Gobi Desert of Mongolia and this specimen was likely discovered during the Central Asiatic Expeditions, the team concluded that this skull was probably acquired by the Delft University between 1940 and 1972 as part of a collection transfer. Sementara Oviraptor dan Protoceratops memang hidup berdampingan di Asia Tengah Kapur akhir , ternyata "pencuri telur" ini mendapat reputasi buruk itu . Los dinosaurios pertenecen al superorden Dinosauria (deinos 'terrible' y sauros 'lagarto' = lagartos terribles) y son el grupo de reptiles con ms xito, incluso ms que los mamferos. There are two documented species: the type genus P. andrewsi and the newly named P. hellenikorhinus. The examined fossil bones indicated that Protoceratops slowed its ontogeny (growth) around 910 years of life, and it ceased around 1113 years. The team concluded that the frill of Protoceratops can be characterized by these ontogenetic changes. In 2010, it was named by Alan L. Titus, Catherine A. Forster, Mark A. Loewen, Andrew A. Farke, Scott D. Sampson, Joshua A. Smith, and Eric M. Roberts. However, they suggested that authentic differences between sexes could be still present in the postcranial skeleton. Preservational bias has been largely ruled out, it is therefore likely that Protoceratops was common in this habitat. While Oviraptor and Protoceratops did coexist in late Cretaceous central Asia, it turns out that this supposed "egg thief" got a bad rapit was . Although it was not fully understood the conditions surrounding their burial, it was clear that they died simultaneously in struggle. They appear to have cared for their young. The ischium was the longest bone of the pelvic girdle. Something like 108 individual dinosaur specimens were collected by the American Museum of Natural History field teams between 1922 and 1925, all but seven of them represented Protoceratops andrewsi. The lacrimal was a near-rectangular bone located in front of the orbit, contributing to the shape of the latter. Stumper. They also observed that the maximum or latest stage of development of the neck frill and nasal horn occurred in the oldest Protoceratops individuals, indicating that such traits were ontogenically variable (meaning that they varied with age).
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