Mesozoic

An average human lifespan is 78 years, which is about 2.46 billion seconds.

A blink of an eye is about a third of a second, or (1/7.38 billionth) of a lifetime.

So now we have a measurement for “a blink of an eye”

For example, a Sequoia Tree has a lifespan of 3500 years, so its “blink of an eye” is 15 seconds.

A “blink of an eye” for the Mesozoic Era is a little over 9 days

Our sun’s “blink of an eye” is 1.35 years.

Extinct Animals of the Cambrian to the Cretaceous!

This will be a limited edition 11x17 print exclusively for sale at spx​ this year!

I love extinct animals, especially lesser-known and non-dinosaur ones. So here are some critters from the Paleozoic through the Mesozoic. Don’t take the period designations too literally, it’s more of a “pretty much around this time” thing, since I couldn’t fit all of them exactly where they should be, scientifically. I’d love to do a sister-image to this with the Cenozoic era!

Here’s a list of the creatures featured!
Cambrian Period
Hallucigenia
Opabinia
Trilobite

Ordovician
Orthoceras

Silurian
Eurypterus
Nektaspida

Devonian
Tiktaalik
Dunkleosteus

Carboniferous
Akmonistion
Pederpes
Arthropleura

Permian
Dimetrodon
Saroctonus

Early Triassic
Erythrosuchus

Middle Triassic
Batrachotomus
Ceresiosaurus

Late Triassic
Oligokyphus

Early Jurassic
Temnodontosaurus

Late Jurassic
Rhamphorhynchus
Pterodactylus
Brachiosaurus
Liopleurodon

Early Cretaceous
Microraptor
Deinonychus
Gobiconodon

Late Cretaceous
Protoceratops
Hesperornis
Corythosaurus

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Tyrannosaurus rex

North America, late evening in the Maastrichtian Age of the Late Cretaceous:

Prey is scarce since the last volcanic eruption, the storm rages on, and the tyrants of Hell Creek are hungry…

[Please don’t use or reproduce without permission, and thanks for viewing!]


Was Tyrannosaurus rex really feathered? Read paleontologist Dr. Dave Hone’s take on the subject here, and Brian Switek’s here.

With a certain major dinosaur-related film approaching, there has been some internet debate on whether or not feathered dinosaurs can be “scary,” or at least intimidating. Read Matthew Martyniuk’s views on feathers and fear, here, and check out Fred Wierum’s image of a rather intimidating feathered Yutyrannus here.

Happy Darwin Day!

Also, you can check out the soundtrack I made for the painting, here.

Mei 

Drawing by Mick Ellison of the American Museum of Natural History, NYC. 

When: Early Cretaceous (~125 million years) 

Where: Liaoning, China

What: Mei is a paravian dinosaur. Paraves is the clade comprised of birds and two families of non-avian dinsaurs; Troodontidae and Dromaeosauridae. As Mei is a fairly basal member of the troodontids, it is not very far removed from the common ancestor of all paravians. Its bird-like heritage can be easily seen in this extraordinary articulated fossil shown above. This specimen was found in a sleeping pose, which is very much like the resting posture of many modern birds, with the legs folded underneath the body and the head folded back and resting on the shoulder.  It is this pose that gives the taxon its full name:  Mei long, which translates to ‘sleeping dragon’. This animal is a sub-adult, determined via the ends of its bones not yet being fused, and would be roughly 21 inches (~53 cm) long, if it was not curled up as it is.  

 The find of a basal troodontid in this pose gives us far more information than just when the sleeping posture was adapted by this clade. It has been determined that modern birds commonly sleep like this to preserve their body heat, covering up the areas that are most prone to radiating heat. If Mei long  and its kin were not 'warm blooded’ than there would be no benefit to sleeping in this pose. Thus, this provides another compelling bit of evidence that the 'warm bloodedness’ of modern birds was present in their mesozoic non-avian relatives. 

Jurassic World: A Park of Inaccuracies

Now, before I get into this, I do want to say that I love the Jurassic Park movies, and I am in no way trying to degrade them or anything. It’s obviously just a movie, inaccuracies are guaranteed. I simply find these little facts amusing, and I imagine you will too.

National geographic summarized it best: the Jurassic Park franchise is based on what we knew about dinosaurs in the 1980’s. Unfortunately, 2015 has proven that the movies have not stood the test of time, and the dinosaurs should look completely different. The producers of Jurassic World have decided to stick with the “classic” dinosaur look, which has lead to debates between either preserving a classic film and its original look, or updating it to current knowledge, but ditching its iconic image.

What are some the inaccuracies of the Jurassic World dinosaurs?

Keep reading

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Quetzalcoatlus - the largest pterosaur 

Reconstructions by Mark Witton. 

When: Late Cretaceous (68-65 million years ago)

Where: North America

What: Quetzalcoatlus is a gigantic pterosaur. Just how gigantic it was has been the subject of some debate, as no 100% complete specimen has been found. While the first estimates put its wingspan at up to 50 feet (16 meters) this has been reduced to 36 feet (11 meters) in the latest studies. The reason for this disparity is due to allometry - the physical properties of bones require that as an animal gets larger its skeletal structure is not just that of a smaller animal made larger. Thus the wing bones of Quetzalcoatlus were relatively thicker than that of a smaller species, and while this was taken into account in the first estimates, it took a better understanding of pterosaur evolution in general for a refined estimate to be generated. 

This large size brings with it another debate: could Quetzalcoatlus fly? The answer is yes, this pterosaur sailed over prehistoric Texas. A big mystery was how Quetzalcoatlus could take off, and recent work by functional morphologists has provided a solution to this puzzle. Pterosaurs differed from all other flying vertebrates in that they retained the majority of the digits on their hand outside of the wing itself; this not only allowed these fingers to be used to manipulate their environment, but was critical for terrestrial locomotion. Quetzalcoatlus was quadrupedal on the ground, like all other pterosaurs, but it had a specially developed system of ligaments and tendons in its wrist joint that allowed it to ‘spring’ up and take flight.  This can be seen in this video.  

Another, more minor, debate is what did Quetzalcoatlus eat? Most pterosaurs are closely associated with large bodies of water and have a fish based diet - but all Quetzalcoatlus remains have been found hundres of miles from ancient shorelines. This, combined with morphology of the skull, has lead to the conclusion that these giants instead fed on smaller vertebrate that they would capture with their large beaks, such as the baby sauropod not having a good day in one of the reconstructions above. 

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Above: Epidermal phenotypes across 75 dinosaur species

Below: Jane, A Very Complete Juvenile Tyrannosaurus Rex

Dinosaur Peacocks of the Mesozoic – Evolution of Feathers

By now most people have at least heard of feathered dinosaurs. Fossils (and fossil chemistry) discovered over the past 20 years have shown unequivocally a progression of integumentary coverings from simple fibers to modern-like feathers and, imagine, even large tail plumes. It is especially the so-called non-avian (i.e., non-bird) theropods (i.e., the group of dinosaurs containing T-Rex and other meat-eaters) , where fossil feathers are prevalent. But how and when did dinosaur feathers evolve? In new research published this week in Biology Letters by Barrett et al. on 75 species with soft tissue preserved, no compelling evidence from was found that the last common ancestor of all dinosaurs possessed feathers or protofeathers. A scaled epidermis is thus the primitive skin form, with feathers evolving later. This research suggests that speculation that all dinosaurs had some sort of feathers or feathery skin covering was just that, speculation. But, it was fun for paleo-artists while it lasted.

Many theropods probably shivered through chilly nights without insulating feathers.

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Les Ptérodactyles, reptiles volants; Les Diplodocus, reptiles terrestres; Les Ichthyosaures, reptiles marins, Mathurin Méheut, 1940s (murals from the Geological Institute of Rennes)

Coiled in stone, bones once sheathed in muscles testify vivid moments now lost. Sinews and skin, fins and wings, membranes and tendons enveloped them—once parts of breathing things that fed and swam and flew and sang songs I will never hear.

Now the skeletons lie flattened, pressed between eons of geologic layers—sediments made of silt and years, piling like mattresses made to hide a princess’ pea, a bed made of rock with sandstone blankets and sheets of shale hiding fish-lizards, pterodactyls, and the Diplodocus.

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Kronosaurus

Mounted specimen on display at Harvard Museum of Natural History

Reconstruction by Jaime Chirinos

When: Cretaceous (~ 125 - 99 million years ago)

Where: Australia

What: Kronosaurus is an australian plesiosaur. Yes, it is a plesiosaur even though it lacks the long neck that many people associated with the group. Plesiosauria is roughly divided into two groups;  Plesiosauroidea - the long necked forms and Pliosauroidea - the short necked forms. Kronosaurus is an example of the latter clade, and shows many of the defining features of this group - such as an enormous head with massive jaws, a short neck, and a relatively short tail- the opposite in many ways of their cousins the plesiosauroids. This australian sea monster was one of the largest of its clade, with estimates of up to 33 feet long (~10 meters). Its teeth reach almost 5 inches (~12 cm ) long in crown length - the part above the gumline. The total tooth would have been over double in size. The large size of its teeth, combined with distinct shape and the lack of clear cutting surfaces also  for their easy identification if they are found as isolated material. 

The Kronosaurus specimen seen above was found in on private property in central Queensland, Australia in the 1920s. A crew from Harvard was shown where the specimen was weathering out, and set about excavating the fossil. After years of work, the specimen was boxed up into over 80 crates, weighing in at over 6 tons and shipped to the states, where it was mounted at the Harvard museum. Decades later the original discoverer of the material finally got the see the results of the preparation and mounting of what he termed ‘his dinosaur’ at the age of 93. In life Kronosaurus was a top predator; there are fossils of Elasmosauridae plesiosaurs that show bite wounds that could have come from Kronosaurus! No fish for this animal, it was after much bigger prey, leading to amazing plesiosaur vs plesiosaur encounters. Or so I like to imagine!