Batrachotomus is big, about 6 meters long, crocodile-line archosaur that lived during the Late Triassic in what’s now Germany. It had an erect posture and was an apex predator in its environment. Medium: Pencils (2b and 5B) on yellow paper Done: 2012

Very small, around 20 centimeters long, ornithodiran (bird-line) archosaur. It lived in Scotland during the Late Triassic. According to some researchers Scleromochlus is a sister-taxon of the clade Pterosauria. Medium: Pencils on yellow paper Done: 2012

Small, Late Triassic in age, gliding sauropsid member of small group of strange Archosauromorph animals. Although Sharovipteryx was able to glide, it’s not directly related to pterosaurs. Medium: Brown ink on yellow paper Done: 2012

Pencil drawing of Odontochelys semitestacea, the oldest known turtle to date. It lived during the Late Triassic in what's now China. Odontochelys had only plastron, the ventral (bottom) part of the armor, lacking solid carapace which is the upper portion of the armor and is typical for more advanced turtles. Medium: Pencil (B, 2B and 5B) Done: 2014 Client: Ivy Press. Illustration for Tennant, J. 2014. Excavate! Dinosaurs: Paper Toy Palaeontology. Ivy Press.

Speculative reconstruction of the ‘prosauropod’ Massospondylus carinatus and the coelophysid theropod Megapnosaurus rhodesiensis. Both animals lived in what’s now Zimbabwe, during the Early Jurassic. Medium: Pencils (2B and 5B) on yellow paper Done: 2013

Speculative reconstruction of the heterodontosaur Pegomastax africanus (only part of the skull is known). It lived during the Early Jurassic, in South Africa. Medium: Pencils (2B and 5B) Done: 2012

Small stegosaur, about 4.5 meters long, from the Middle Jurassic of China. It’s the most basal stegosaur known to date, and unlike most of the other stegosaurs it’s characterized by fairly long forellimbs in comparison to legs, wide skull and the presence of premaxillary teeth. Medium: Pencils (2B and 5B) Done: 2013

Up to 7 meters long Chinese stegosaur, that lived during the Late Jurassic. Medium: Pencils (2B and 5B) Done: 2013

Small stegosaur from the Late Jurassic of China. It’s easily distinguished from other stegosaurs because of its very big shoulder spikes. Forelimbs appear to be relatively short and robust. Medium: Pencils (2B and 5B) Done: 2013

One of the smallest stegosaurs, Chungkingosaurus lived in what’s now China during the Late Jurassic. It shared its habitat with another stegosaur – Tuojiangosaurus. Medium: Pencils (2B and 5B) Done: 2013

One of the many beautifully preserved Chinese feathered non-avian dinosaur. Eosinopteryx was small (about 30 centimeters long) paravian theropod that lived in the Late Jurassic. The name Eosinopteryx mean “Dawn Chinese feather”. Medium: Pencils (2B and 5B) Done: 2013

Reconstruction of the salamandroid Beiyanerpeton jianpingensis. It lived during the Late Jurassic in what's now China. Medium: Pencil (B, 2B and 5B) Done: 2014 Client: Ivy Press. Illustration for Tennant, J. 2014. Excavate! Dinosaurs: Paper Toy Palaeontology. Ivy Press.

Stegosaurid dinosaur from the Late Jurassic of Tanzania. It is about the same size as Huayangosaurus. Medium: Pencils (2B and 5B) on yellow paper Done: 2013

‘Sauropod-mimic’ stegosaurid from the Late Jurassic of Portugal. Miragaia is among the bigger stegosaurs, with estimated length of about 6 meters. Typical for this taxon is the elongated neck which superficially resembles that of sauropod dinosaurs. The long neck is probably an adaptation for feeding on taller plants, or result of sexual selection. Medium: Pencils (2B and 5B) Done: 2013

One of the biggest stegosaurs (others being Stegosaurus and Dacentrurus), Hesperosaurus lived during the Late Jurassic, in the same are as Stegosaurus (the Morrison formation, USA). Due to its slightly older age, some paleontologists think that Hesperosaurus is direct ancestor of Stegosaurus. It’s characterized by more rounded plates than the latter. Here, the animal is depicted while taking a mud bath. Medium: Pencils (2B and 5B) Done: 2013

Reconstruction of the stegosaur Stegosaurus ungulatus. Medium: Pencil Done: 2013

Reconstruction of the stegosaur Stegosaurus stenops. It lived in what is now USA, during the Late Jurassic. Medium: Ink. Done: 2014. Artwork for the National Museum of Natural History, Sofia.

Stegosaurus stenops spiking hungry Allosaurus fragilis in last attempt to fend off the predator. Medium: Pencils (B, 2B and 5B) Done: 2014 Client: Ivy Press. Illustration for Tennant, J. 2014. Excavate! Dinosaurs: Paper Toy Palaeontology. Ivy Press.

Reconstruction of the theropod Allosaurus fragilis. Allosaurus is one of the biggest Jurassic meat-eating dinosaur. It lived during the Late Jurassic in what is now USA. Medium: Ink. Done: 2014. Artwork for the National Museum of Natural History, Sofia.

Reconstruction of the heterodontosaurid Fruitadens haagarorum. With estimated length of about 70 cm., it is one of the smallest known non-avian dinosaurs. It lived during the Late Jurassic in what is now USA. Medium: Watercolors. Done: 2014. Client: Ivy Press. Illustration for Tennant, J. 2014. Excavate! Dinosaurs: Paper Toy Palaeontology. Ivy Press.

A species of Late Jurassic sauropod dinosaur from the Morrison formation, USA. Kaatedocus is close relative of Diplodocus. Medium: Brown ink on yellow paper Done: 2012

Giraffatitan brancai (formerly known as Brachiosaurus brancai) stripping the branches of an Araucaria-like tree. Medium: Pencil (B, 2B and 5B) Done: 2014 Client: Ivy Press. Illustration for Tennant, J. 2014. Excavate! Dinosaurs: Paper Toy Palaeontology. Ivy Press.

Reconstruction of the spinosaurid Baryonyx walkeri. As with all spinosaurids, major part of Baryonyx's diet consisted of fish. It lived in Europe during the Early Cretaceous. Medium: Ink. Done: 2014. Artwork for the National Museum of Natural History, Sofia.

While other stegosaurs are know from the Jurassic, Wuerhosaurus is from the Early Cretaceous. It lived in China. This reconstruction is speculative due to the very fragmentary nature of the fossils of this animal. Medium: Pencils (2B and 5B) Done: 2013

This theropod is among the bigger compsognathids, with length of about 1.8 meters, but also it the basal-most member of the group. It lived in what’s now China during the Early Cretaceous. Medium: Pencils (2B and 5B) Done: 2013

Reconstruction of the famous four-winged Chinese dromaeosaur. It lived during the Early Cretaceous. Here, Microraptor is depicted suffering from fire injury. Medium: Pencils (2B and 5B) Done: 2013

Two individuals of the polacanthin ankylosaur species Gastonia burgei minding their own business, whether it is sniffing the ground for leafs, twigs or cones, or staring curiously at their own shadow, at dusk, while three big sauropods – Cedarosaurus weiskopfae, wander in the background. The scene takes place in Utah (USA) during the Early Cretaceous, about 126 million years ago. Medium: Acrylics Done: 2014

Reconstruction of the giant carcharodontosaurid theropod Acrocanthosaurus atokensis. Almost as long as the famous Tyrannosaurus, Acrocanthosaurus lived in what is now USA, during the Early Cretaceous. Medium: Ink. Done: 2014. Artwork for the National Museum of Natural History, Sofia.

Futalognkosaurus is gigantic, over 25 meters long, titanosaurian sauropod that lived during the Coniacian state of the Late Cretaceous. Its fossils were found in Argentina in 2000, and published 7 years later. Medium: Brown ink on yellow paper Done: 2012

Reconstruction of Cyclobatis major, a prehistoric skate (kind of ray fish) from the Late Cretaceous of Lebanon. Medium: Watercolors Done: 2014 Client: Ivy Press; illustration for Tennant, J. 2014. Excavate! Dinosaurus: Paper Toy Palaeontology. Ivy press.

Reconstruction of the tyrannosaurid theropod Lythronax argestes. It lived during the Campanian (Late Cretaceous) in what is now USA. Medium: Ink Done: 2013

Both animals lived in Gobi (Mongolia) during the Campanian stage of the Late Cretaceous. Velociraptor and Protoceratops are the most common dinosaurs in their environment, and there is fossil evidence that they have engaged in predator-prey interactions. Medium: Pencils (2B and 5B) Done: 2013

Reconstruction of the tyrannosaurid theropod Bistahieversor sealeyi. It lived in what is now USA during the Campanian (Late Cretaceous). Medium: Ink Done: 2013

The tyrannosaurid Gorgosaurus libratus jumping on unseen small prey. Medium: Ink Done: 2013

The tyrannosaurid Daspletosaurus torosus during some sort of speculative visual display. Medium: Ink Done: 2013

Drawing of a juvenile individual of the lambeosaurin hadrosaurid species Parasaurolophus walkeri. The reconstruction is based on the specimen RAM 14000. Medium: Pencil (B, 2B and 5B) Done: 2014 Client: Ivy Press. Illustration for Tennant, J. 2014. Excavate! Dinosaurs: Paper Toy Palaeontology. Ivy Press.

Reconstruction of the hadrosaurid Lambeosaurus lambei. It lived during the Campanian in what is now Canada. Medium: Ink. Done: 2014. Artwork for the National Museum of Natural History, Sofia.

Reconstruction of the ceratopsid Pachyrhinosaurus canadensis. It lived in what is now Canada, during the Campanian. Medium: Ink. Done: 2014. Artwork for the National Museum of Natural History, Sofia.

Reconstruction of the nodosaurid ankylosaur Edmontonia longiceps. It lived in what is now Canada, during the Campanian. Medium: Ink. Done: 2014. Artwork for the National Museum of Natural History, Sofia.

Extremely speculative (in sense of animal behavior) reconstruction of the pachycephalosaur Prenocephale. It lived in the forests of Mongolia during the Late Cretaceous. Medium: Pencils (2B and 5B) Done: 2013

Reconstruction of the tyrannosaurid Alioramus remotus. Mediun: Ink Done: 2013

Reconstruction of the tyrannosaurid (or non-tyrannosaurid tyrannosauroid) Alioramus altai. It lived in what's know Mongolia during the early Maastrichtian (Late Cretaceous). Medium: Ink Done: 2014

The tyrannosaurid Tarbosaurus bataar while sunbathing (speculative behavior). Medium: Ink Done: 2013

Reconstruction of the therizinosauroid theropod Therizinosaurus cheloniformis. Unlike the majority of theropods, therizinosauroids were herbivorous. Therizinosaurus lived alongside Tarbosaurus in what is now Mongolia, during the Late Cretaceous. Medium: Ink. Done: 2014. Artwork for the National Museum of Natural History, Sofia.

Reconstruction of the tyrannosaurid theropod Zhuchengtyrannus magnus. It lived during the Late Cretaceous in what is now China. Medium: Ink Done: 2013

Reconstruction of Albertosaurus sarcophagus, a tyrannosaurid theropod from Canada. It lived during the early Maastrichtian age of Late Cretaceous. Medium: Ink Done: 2013

Speculative reconstruction of the putative Bulgarian ornithomimosaur. Medium: Ink. Done: 2014. Artwork for the National Museum of Natural History, Sofia.

Speculative life reconstruction of the putative Bulgarian ornithomimosaur. Medium: Acrylics. Done: 2014. Client: Science Center for Kids "Muzeiko", Sofia.

Speculative illustration of what a complete skeleton of ornithomimosaur may look like if preserved under very good conditions. Skeleton based on the hypothetical life reconstruction of the putative Bulgarian ornithomimosaur. Medium: Acrylics. Done: 2014 Client: Science Center for Kids "Muzeiko", Sofia.

Speculative life reconstruction of the putative Bulgarian ornithomimosaur. Medium: Acrylics. Done: 2014 Client: Science Center for Kids "Muzeiko", Sofia.

Reconstruction of Mosasaurus cf. hoffmanni (front) and undetermined Bulgarian hadrosauroid (background). Medium: Acrylics. Done: 2014. Client: Science Center for Kids "Muzeiko", Sofia.

Medium: Acrylics. Done: 2014. Client: Science Center for Kids "Muzeiko", Sofia.

Speculative reconstruction of the undetermined Bulgarian hadrosauroid. Medium: Ink. Done: 2014. Artwork for the National Museum of Natural History, Sofia.

Reconstruction of the titanosaurian sauropod Ampelosaurus atacis. It lived in what is now France during the Maastrichtian. Medium: Ink. Done: 2014. Artwork for the National Museum of Natural History, Sofia.

Ornitomimosauria is a group of coelurosaurs which members were long thought to have been feathered (there is evidence for feathers in all other coelurosaurian groups), but there were no actual fossils to confirm this. The breakthrough came in October 2012, when paper was published describing three specimens of Ornithomimus at different ontogenetic stages with preserved feathers. Medium: Pencils (2B and 5B) Done: 2012

Dryptosaurus is tyrannosauroid theropod, contemporaneous with Tyrannosaurus, but while T. rex inhabited the western subcontinent Laramida, Dryptosaurus roamed the eastern subcontinent Appalachia. Dryptosaurus is estimated to be around 7.5 meters long. It had very big hand claws and was apex predator of its environment. Medium: Pencils (2B and 5B) Done: 2013

Reconstruction of the "dwarf" tyrannosaurid Nanuqsaurus hoglundi. This theropod lived beyond the arctic circle during the Maastrichtian (Late Cretaceous). Its fossils are found in Alaska. Medium: Ink Done: 2014

Medium: Watercolor Done: 2013 Client: Ivy Press; illustration for Tennant, J. 2014. Excavate! Dinosaurs: Paper Toy Palaeontology. Ivy Press.

Medium: Watercolors and ink Done: 2014

Medium: Ink Done: 2013

An artwork depicting part of the archosaurian diversity of Hell Creek Formation, USA: Tyrannosaurus rex (center; non-avian theropod), Brachychampsa montana (down left; alligatoroid), Thescelosaurus neglectus (down right; ornithopod), and Avisaurus archibaldi (top; avian theropod). Medium: Ink Done: 2013

Medium: Ink. Done: 2014. Artwork for the National Museum of Natural History, Sofia.