An ongoing dinosaur encyclopedia. My main tumblr URL is Dinostuck. I also run A Pterosaur A Day. Also I am a cofounder of the dinodorks fandom :)

A Dinosaur A Day

A Field Guide To Dinosaurs

Hey guys

Giant physics test on Thursday

Can’t do a dinosaur till that’s over 


Streptospondylus altdorfensis


NameStreptospondylus altdorfensis (possible other species S. cuvieri.) 

Name Meaning: Altdorf Reversed Vertebra

First Described: 1832

Described By: von Meyer 

ClassificationDinosauria, Saurischia, Theropoda, Neotheropoda, Averostra, Tetanurae, Megalosauroidea, Megalosauria 

Streptospondylus was a theropod from the Callovian/Oxfordian stage of teh Middle Jurassic, about 161 million years ago. It was found in Lower Normandy in France. Streptospondylus has a tumultuous paleontological history, first excavated in 1770 (making it possible to have been the first dinosaur scientifically recognized.) It was originally described as a crocodile by Georges Cuvier. After Megalosaurus was described, it was still not renamed. It was finally described by Von Meyer after he examined a contemporaneous crocodile, Metriorhynchus. Richard Owen named several species of Streptospondylus, but it has since been found that many of these are actually forms of IguanodonS. cuvieri, however, is still considered a dubious species of this genus. In the 1960s it was removed as a genus and named a species of Eustreptospondylus, but it was eventually replaced in its own genus. It is known from little fossil material and so not much is known about it, other than that it is a theropod and a predator, as well as bipedal. Its full size isn’t established but it was probably 7 meters long. Magnosaurus was its close relative. 


Shout out goes to nabolling96!

Piatnitzkysaurus floresi


NamePiatnitzkysaurus floresi 

Name Meaning: Piatnitzky’s Lizard

First Described: 1979

Described By: Bonaparte

ClassificationDinosauria, Saurischia, Theropoda, Neotheropoda, Averostra, Tetanurae, Megalosauroidea 

Piatnizkysaurus was a meaglosaurid theropod from the Callovian Middle Jurassic Period, about 164 to 161 million years ago. It was found in the Canadon Asfalto Formation in Argentina and was about 4.3 meters long, making it a medium sized theropod. It probably hunted smaller dinosaurs and even some larger ones, as well as scavengened. It lived alongside such animals as Eoabilsaurus, Patagosaurus, Volkheimeria, Tehuelchesaurus, and Condorraptor, but was probably most closely related to Piveteausaurus. It is known from two partial skeletons. 


Shout out goes to avisuchian!

Marshosaurus bicentesimus



NameMarshosaurus bicentesimus 

Name Meaning: Marsh’s Bicentennial Lizard

First Described: 1976

Described By: Madsen

ClassificationDinosauria, Saurischia, Theropoda, Neotheropoda, Averostra, Tetanurae, Megalosauroidea 

Marshosaurus was a medium sized theropod from the Kimmeridgian stage of the Late Jurassic, about 157.3 to 152.1 million years ago. It was found in the Morrison Formation of Utah and also in Colorado, as it was possible it was found in the Cleveland-Lloyd Quarry. It was a medium sized theropod, about 4.5 meters long. It was originally placed in many different theropod groups, including Avetheropoda. However, it was later found to be a megalosauroid, very similar to Megalosaurus. It probably died due to injuries in the rib and ilium. It lived in a shallow marine and semiarid environment, with distinct wet and dry seasons. It was absolutely full of dinosaurs, with basins of swampy lowlands and lakes, as well as floodplains. It lived alongside such famous dinosaurs as Camarasaurus, Barosaurus, Diplodocus, Apatosaurus, Brachiosaurus, Camptosaurus, Stegosaurus, Othnielosaurus, Saurophaganax, Torvosaurus, Ceratosaurus, Stokeosaurus, Ornitholestes, and Allosaurus. There were also many early mammals, many cycads and ginkgoes and conifers, as well as ferns. It was named in honor of famous palaeontologist Othniel Charles Marsh, one of the lead palaeontologists of the great American Bone Wars. His other namesake, Othnielosaurus, might have been hunted by Marshosaurus


Shout out goes to megacosms!



Hi folks! 

I am so happy that so many of you guys are following this blog. So happy. We are up to 305 and counting! 

So here’s a little giveaway I’m going to do as a thank you to you all. I will not spam this blog with it. It won’t be like that. 


- You gotta be following a-dinosaur-a-day. The whole point of this is to thank you guys for your continual support and interest in this blog 

- You can reblog this post once to get your name in for the giveaway. You can like this post too. Thus you can have your “name” in the pot a grand total of two times. Don’t spam your followers, either! Just two entries. 

- 1 First Prize Winner will receive a fluffy adorable Build-A-Dino from here: Build a Dino. You can pick any one you want! I’ll need your address to send it to you. Any country is okay! 

- 7 Second Prize Winners will get THEIR FAVORITE DINOSAUR featured in my Featured Dinosaur Week! Basically I will go out of my predetermined order to put any dinosaurs not already done as the dinosaur of the day one of the days of that week! You will also be given a shout out on that day :) 

The giveaway will end on JUNE 16TH! Nothing after that date will count! 

I hope you guys realize how much your continual support and encouragement for this blog has really helped it along. I feel like I’m making something awesome and that you guys are all enjoying it! 

So please reblog and like, and may the odds be ever in your favor :)

For financial reasons I’m extending the giveaway until June

Condorraptor currumili


NameCondorraptor currumili 

Name Meaning: Robber from Cerro Condor

First Described: 2005

Described By: Rauhut

ClassificationDinosauria, Saurischia, Theropoda, Neotheropoda, Averostra, Tetanurae, Megalosauroidea 

Condorraptor was a megalosauroid dinosaur from the Canadon Asfalto Formation in Argentina, during the Middle Jurassic Period (anywhen from 174.1 million years ago to 163.5 mya). It is based only on a tibia, though there is a partial skeleton that might be from the same individual. It is a Megalosauroid and is closely related to Piatnitzkysaurus. It shared its habitat with EoabelisaurusPatagosaurusPiatnitzkysaurus, TehuelchesaurusManidens, and Volkheimeria. 


Shout out goes to jenocide666!

UGH and because I got so little sleep last night, today I feel too crappy to do one. I’m sorry guys :(


It finally happened
My dinosaur blog is more popular than my personal blog
Had to happen sometime
Don’t know whether to be proud for the Dino or disappointed in the personal

No animals today guys; I have to be up ungodly early tomorrow to register for class

Valdoraptor oweni


NameValdoraptor oweni

Name Meaning: Wealden Plunderer

First Described: 1991 

Described By: Olshevsky 

ClassificationDinosauria, Saurischia, Theropoda, Neotheropoda, Averostra, Tetanurae 

Valdoraptor was an early tetanuran from the Early Cretaceous of England, and is only known from partial foot bones. It was originally discovered by Richard Owen, and named a species later of Megalosaurus, but mistook the foot fossils for different parts of the foot. It was then later described as its own species. It is known from a damaged specimen and was probably similar to Neovenator and Eotyrannus, but probably was its own genus and not a nomen dubium. It can’t be described as any more than a basal tetanuran. 


Shout out goes to jamatadon!

Monolophosaurus jiangi


NameMonolophosaurus jiangi 

Name Meaning: Single Crested Lizard 

First Described: 1993

Described By: Zhao & Currie

ClassificationDinosauria, Saurischia, Theropoda, Neotheropoda, Averostra, Tetanurae, Megalosauroidea 

Monolophosaurus was an early tetanuran from the Shishugou Formation in Xinjiang, China, and is named for the distinctive single crest on the top of its skull. It was about 5 meters long and probably lived on lake or ocean shores. It is from the Callovian stage of the middle Jurassic, about 165 million years ago. It is known from a nearly complete skeleton and was originally named a megalosaur, but it has also been described as many different groups. It also has been described as a basal tetanuran. The firm classification is still up for debate. It was, however, probably very closely related to Chuandongocoelurus. The crest was hollow, functioning as a weight saving system. 


Shout out goes to paperstreetsoapinc!

Kayentavenator elysiae


NameKayentavenator elysiae 

Name Meaning: Kayenta Hunter

First Described: 2010

Described By: Gay

ClassificationDInosauria, Saurischia, Theropoda, Neotheropoda, Averostra, Tetanurae 

Kayentavenator is a small theropod from the Kayenta Formation in northeastern Arizona, and dates back to the Sinemurian/Pliensbachian stages of the early Jurassic, about 189 million years ago. It is known from a partial skeleton, and a juvenile one at that, so the exact size of the animal can’t be estimated. It is definitely distinct from the contemporaneous Dilophosaurus. It was originally a species of Syntarsus (Megapnosaurus), but has later been given its own genus due to many tetanuran characteristics, such as pubic fenestra and a ridge on the tibia. It probably was closely related to Allosaurus and was the oldest tetanuran in North America. It shared its habitat with the prey items Sarahsaurus and Scutellosaurus, and the rival Megapnosaurus. It probably was a prey item of Dilophosaurus. It probably lived in a river environment with a seasonal climate.


Shout out goes to alilbitofeverythingg!

Kaijiangosaurus lini


NameKaijiangosaurus lini 

Name Meaning: Lin’s Kiijiang lizard 

First Described: 1984 

Described By: He

ClassificationDinosauria, Saurischia, Theropoda, Neotheropoda, Averostra, Tetanurae 

Kaijiangosaurus was another basal tetanuran from the Bathonian to the Callovian stages of the Middle Jurassic period, or from 168.3 to 163.5 million years ago. It was discovered in the Xiashaximiao Formation in China (once again, another basal tetanuran from Eurasia.) It was about five meters long and is known from a fragmentary skeleton lacking the skull, and another specimen with a fragmentary skull. However, the remains overall are very fragmentary, making it hard to place it exactly in the theropod family tree. It is a possible Megalosaurid, due to its teeth, and it is possibly synoymous with Gasosaurus. It had strongly curved claws on the hand. It could be a primitive carnosaur. 


Shout out goes to zindafar!

Illiosuchus incognitus


Name: Illiosuchus incognitus 

Name Meaning: Unknown Crocodile Hipped

First Described: 1932

Described By: Huene

ClassificationDinosaura, Saurischia, Theropoda, Neotheropoda, Averostra, Tetanurae 

Illiosuchus is a basal Tetanuran from the Bathonian Stage of the middle Jurassic period, about 169.2 to 164.4 million years ago. It is known from the Stonesfield Slate of Oxfordshire, England, making it another early Tetanuran from Europe. It is theorized that perhaps the ancestor to the group arose in the area, given the prevalence of the basal Tetanuran group there, the Megalosauroids. It was probably 1.5 meters long, making it a smaller theropod. It had similar ridges on its pelvic bone similar to other Tetanurans, but especially similar to the Tyrannosaurs; as such, it has been hypothesized as an ancestor to that group, but this is unlikely. If it is, it would be the earliest one by several million years. It also could be a small/juvenile individual of the genus Megalosaurus. As such, it is considered a dubious genus. 


Shout out goes to kampelife!

Cruxicheiros newmanorum


Name: Cruxicheiros newmanorum 

Name Meaning: Newman’s Cross Hand

First Described: 2010 

Described by: Benson & Radley 

ClassificationDinosauria, Saurischia, Theropoda, Neotheropoda, Tetanurae 

Cruxicheiros was a tetanuran from the Bathonian stage of the middle Jurassic, about 167 million years ago. it was discovered in the Cross Hands Quarry in Warwickshire, England. Originally the specimen was described as Megalosaurus, though later enough differences were found for it to be assigned its own species in honor of where it was found. It is known from limited material, and as such not much is known about it. It was a large animal, about 20 feet long, and definitely a tetanuran, though probably a basal one. These early tetanurans show how the beginnings of the clade probably originated in Europe/Asia, especially due to the Megalosaurid family living in that area. 


Shout out goes to fisjones!