10 Non-Dinosaur Cretaceous Creatures

Quck answer

While dinosaurs are the most famous animals of the Cretaceous period, there were plenty of other creatures that lived alongside them. Here are 10 animals that weren’t dinosaurs but were just as fascinating:

1. Pterosaurs – flying reptiles with wingspan of up to 33 feet

2. Mosasaurs – large marine reptiles that resembled modern-day crocodiles

3. Ammonites – sea creatures with coiled shells that could grow up to 3 feet in diameter

4. Ichthyosaurs – aquatic reptiles that looked like dolphins or sharks

5. Hesperornis – flightless birds that lived in the water and had sharp teeth

6. Ankylosaurs – armored dinosaurs with club tails

7. Plesiosaurs – long-necked marine reptiles with paddle-like limbs

8. Trilobites – prehistoric arthropods with hard exoskeletons

9. Belemnites – squid-like creatures with internal shells

10. Mammals – although small and relatively insignificant at the time, mammals were present during the Cretaceous period and would eventually become the dominant land animals after the dinosaurs went extinct.

Animal Facts

While dinosaurs get all the attention, there were other fascinating creatures that roamed the Earth during the Cretaceous period.
В© Bill Varie/Corbis

65 million years ago, a massive asteroid or comet collided with Earth, causing widespread destruction and leading to the end of the Cretaceous Period. This period was dominated by the dinosaurs, such as the massive sauropods and the ferocious tyrannosaurs. However, as the planet changed and new habitats emerged, many other species thrived alongside the dinosaurs. Some of these species still exist today, while others have gone extinct.

One such creature is the louse, a tiny parasite that has been around since the days of the dinosaurs. Originally found on the downy feathers of avian-dinosaurs, lice have managed to survive the mass extinction event and continue to thrive today.

10: Lice

Lice may be itchy and unpleasant, but they have managed to survive for millions of years.
В© Eva-Maria Pasieka/Corbis

Despite their small size, lice have proven to be incredibly resilient. Fossilized lice have been found that date back millions of years, and researchers believe that these parasites not only survived the extinction event but also flourished afterward.

While lice may not be the most glamorous creatures, they serve as a reminder that there were many other fascinating species that lived during the Cretaceous period.

9: Cockroaches

Cockroaches are incredibly resilient creatures, as they have been around for much longer than dinosaurs. A geology student at Ohio State University discovered the largest-ever fossil of a complete cockroach, which was 3.5 inches (9 centimeters) long and 300 million years old. Scientists were able to observe the veins in its wings, legs, and antennae. Cockroaches survived long before and after the Cretaceous Period, during which they fed on dinosaur excrement, according to some researchers. A group of scientists at the Slovak Academy of Sciences discovered bits of wood in the gut of a 120 million-year-old cockroach fossil, which they believe came from dinosaur excrement, using a sophisticated imaging method called synchrotron X-ray microtomography.

8: Devil Frogs

Madagascar was home to the Beelzebufo ampinga, also known as the “devil frog,” which was perhaps the largest frog that ever lived in the Cretaceous Period, measuring 16 inches (41 centimeters) long and towering over the largest modern frog by 3.5 inches (8.9 centimeters). This frog was so large that it probably ate smaller frogs, lizards, and mice, and possibly even baby dinosaurs. Koolasuchus, another amphibian that lived during the Cretaceous Period, was a half-ton giant with eyes on the top of its head and liked to stay in cooler regions but didn’t fare well in warmer conditions.

7: Ancient Lobsters

Lobsters are a popular seafood dish today, but they are also an evolutionary marvel. They survived the Late Cretaceous mass extinction, outlasting even the fearsome T. rex. Lobsters are incredibly resilient creatures and have been around for millions of years. Lobsters beat extinction and became one of the tastiest dishes on today’s menu. The fossil of a Late Jurassic lobster shows how long these creatures have been around.

During the Late Cretaceous Period, there were many decapoda crustaceans, including lobsters, crayfish, and shrimp. Fossilized evidence of 22 decapoda crustacean species has been found in British Columbia, Canada, with less than half becoming extinct by the end of the period. One of the surviving species is the sea turtle, which evolved from land creatures to become sea dwellers. The now extinct Atlantochelys mortoni was one of the largest ancient sea turtles, while the plesiosaurs were among the gigantic marine reptiles that did not survive the extinction. Various lizard species lived alongside the dinosaurs, but 85% of all snake and lizard species disappeared once the asteroid struck. Polyglyphanodontia was one broad category of lizards that was wiped out, and it took about 10 million years after the Cretaceous Period for lizards to make a comeback. The Cretaceous Period also saw the emergence of many crab species, including the oversized Megaxantho zogue with a curved tooth on its right claw.

During the Cenozoic Era, modern crabs evolved from species of crabs that inherited features of M. zogue, which did not survive the great extinction. Some Cretaceous crabs had both male and female characteristics, with some living in present-day South Dakota. These intersex crabs were caused by contaminated habitats or prehistoric barnacles that affected their hormones. Toothless pterosaurs were the first animals, besides insects, to fly by flapping their wings and lived during the last age of the dinosaurs, ruling the skies with wings up to 40 feet long. Pterosaurs were related to the dinosaurs but not dinosaurs themselves. Vintana sertichi, a groundhog-like mammal, lived during the Cretaceous and was larger than most mammals at 20 pounds. It belonged to a group of mammals known as Gondwanatherians, which developed on the land mass known as Gondwana.

1: Ancient Rodents

Rugosodon eurasiaticus, which lived during the Cretaceous period and became extinct around 35 million years ago, was a small, versatile rodent-like mammal that was about the size of a chipmunk. The earliest known fossil of R. eurasiaticus dates back to the Jurassic period, about 160 million years ago.

When the fossil was discovered in 2013, scientists determined that R. eurasiaticus was a precursor to other mammals that ate plants and lived in trees. These multituberculates were successful during the Cretaceous period, and they had the ability to jump, climb trees, and dig tunnels. Rodent-like mammals first appeared during the Jurassic period and survived for more than a million years. Some were as tiny as mice, while others were as big as beavers. [Sources: Science, Yandell, AAAS]

More Information

Author’s Note: Ten Non-Dinosaur Cretaceous Animals

Some scientists believe that the Chicxulub asteroid was responsible for the extinction of the dinosaurs, while others believe that the mass extinction happened 300,000 years before or 180,000 years after the Cretaceous period. New evidence suggests that another asteroid may have struck India, causing the extinction. Some scientists think that a series of volcanic eruptions could have been the cause.

Articles on the same topic

Is the world facing a sixth mass extinction?
Tips for surviving a mass extinction event
How can scientists determine the sex of dinosaurs?
9 extinct sea creatures that were once exotic
10 terrifying extinct whales and dolphins

Additional resources

University of California Museum of Paleontology: The Cretaceous Period
Facts about the animals, plants, and climate of the Cretaceous Period on LiveScience
Encyclopedia Britannica information on the Cretaceous Period

Sources

American Association for the Advancement of Science (AAAS). вЂњUnearthed: Fossil of history’s most successful mammal.вЂќ Aug. 15, 2013. (March 2, 2015) http://www.eurekalert.org/pub_releases/2013-08/aaft-ufo080913.php
Amos, Jonathan. вЂњMonster turtle fossils re-united.вЂќ BBC. March 24, 2014. (March 1, 2015) http://www.bbc.com/news/science-environment-26717415
Balter. Michael. вЂњDid Feathered Dinos Spread Lice?вЂќ Science. April 6, 2011. (Feb. 27, 2015) http://news.sciencemag.org/paleontology/2011/04/did-feathered-dinos-spread-lice
BBC. вЂњKoolasuchus.вЂќ (March 1, 2015) http://www.bbc.co.uk/nature/life/Koolasuchus
CBC News. вЂњLargest cockroach fossil predates dinosaurs.вЂќ Nov. 13, 2001. (Feb. 27, 2015) http://www.cbc.ca/news/technology/largest-cockroach-fossil-predates-dinosaurs-1.299004
CBC News. вЂњLizards, snakes almost went extinct with dinosaurs.вЂќ Dec. 12, 2012. (Feb. 26, 2015) http://www.cbc.ca/news/technology/lizards-snakes-almost-went-extinct-with-dinosaurs-1.1266168
Choi, Charles Q. вЂњDinosaurs Likely Lousy With Lice.вЂќ LiveScience. April 5, 2011. (Feb. 27, 2015) http://www.livescience.com/13577-dinosaur-lice-ancient-parasites.html
Drake, Nadia. вЂњFossil From Dinosaur Era Reveals Big Mammal With Super Senses.вЂќ National Geographic. Nov. 5, 2014. (March 2, 2015) http://news.nationalgeographic.com/news/2014/11/141105-mammal-evolution-vintana-fossil-science/
Encyclopedia Britannica. вЂњGondwana.вЂќ (March 2, 2015) http://www.britannica.com/EBchecked/topic/238402/Gondwana
Lewis. Tanya. вЂњCockroaches Munched on Dinosaur Poop.вЂќ Dec. 6, 2013. (March 1, 2015) http://www.livescience.com/41735-cockroaches-ate-dinosaur-poop.html
Lucy Martha Evelyn and Vachik Hairapetian. вЂњA new lobster Paraclytia valashtensis (Crustacea, Decapoda, Nephropidae) from the Late Cretaceous of the central Alborz Range, Iran.вЂќ PalГ¤ontologische Zeitschrift. September 2009. (March 1, 2015) http://link.springer.com/article/10.1007%2Fs12542-009-0033-5
Maynard, James. вЂњToothless pterosaurs (no, not Night Fury) once ruled Late Cretaceous skies.вЂќ Tech Times. (March 2, 2015) http://www.techtimes.com/articles/13470/20140820/toothless-pterosaurs-no-not-night-fury-once-ruled-late-cretaceous-skies.htm
Moskowitz, Clara. вЂњHuge Frog Was Eating Machine.вЂќ LiveScience. Feb. 17, 2008. (March 1, 2015) http://www.livescience.com/4820-huge-frog-eating-machine.html
National Geographic. вЂњCretaceous Period.вЂќ (Feb. 27, 2015) http://science.nationalgeographic.com/science/prehistoric-world/cretaceous/
National Geographic. вЂњDevil Frog.вЂќ (March 1, 2015) http://animals.nationalgeographic.com/animals/prehistoric/devil-frog/
Ohio State University. вЂњLargest Fossil Cockroach Found; Site Preserves Incredible Detail.вЂќ Science Daily. Nov. 21, 2001. (Feb. 27, 2015) http://www.sciencedaily.com/releases/2001/11/011120053611.htm
Pappas, Stephanie. вЂњCrazy Cretaceous Find: Intersex Crabs.вЂќ LiveScience. Nov. 13, 2013. (Feb. 26, 2015) http://www.livescience.com/41156-cretaceous-intersex-crabs.html
Pterosaur.Net. вЂњImportant Species.вЂќ (March 2, 2015) http://pterosaur.net/species.php
Prostak, Sergio. вЂњStudy: Chicxulub Asteroid Wiped Out Obamadon and Many Other Cretaceous Lizards, Snakes.вЂќ Sci-News.com. Dec. 11, 2012. (Feb. 26, 2015) http://www.sci-news.com/paleontology/article00772.html
Ramanujan, Krishna. вЂњA chance discovery in Mexico leads Cornell scientist to rewrite fossil history of shell-breaking crab.вЂќ Cornell University. April 16, 2008. (Feb. 26, 2015) http://www.news.cornell.edu/stories/2008/04/cornell-researcher-finds-fossilized-shell-breaking-crab
Schweitzer, C.E.; Feldmann, R.M.; Fam, J.; Hessin, W.A.; Hetrick, S.W.; Nyborg, T.G;. Ross R.L.M. вЂњCretaceous and Eocene Decapod Crustaceans from Southern Vancouver Island, British Columbia, Canada.вЂќ NRC Research Press. 2003. (March 1, 2015) http://www.nrcresearchpress.com/doi/book/10.1139/9780660190921#.VPSDu_nF-Sq
Sci-News.com вЂњPaleontologists Find Fossil Bone of Giant Turtle Atlantochelys mortoni.вЂќ April 3, 2014. (March 1, 2015) http://www.sci-news.com/paleontology/science-giant-turtle-atlantochelys-mortoni-01825.html
Science. вЂњEarliest Evolution of Multituberculate Mammals Revealed by a New Jurassic Fossil.вЂќ Aug. 16, 2013. (March 2, 2015) http://www.sciencemag.org/content/341/6147/779
St. CatherineвЂ™s Island Sea Turtle Conservation Program. вЂњLife History. Cretaceous Sea Turtle Nests.вЂќ (March 1, 2015) http://www.scistp.org/lifehistory/cretaceous.php
Switek.

The articles referenced include a study on fossil lice revealing their success in evolution, an article on the rise of modern mammals long after the demise of dinosaurs, a resource on the Cretaceous period, and a discovery of an ancient mammalian fossil. All sources were accessed in March 2015. The original HTML formatting and image tags have been retained.

FAQ

1. What is the Cretaceous period?

The Cretaceous period was the last period of the Mesozoic era, lasting from 145 to 66 million years ago. It is best known for being the time when dinosaurs roamed the Earth, but it was also a time of great diversification for other animals.

2. What are some animals that lived during the Cretaceous period?

Aside from dinosaurs, some animals that lived during the Cretaceous period include pterosaurs, mosasaurs, ichthyosaurs, ammonites, and various types of plants and invertebrates.

3. What are some non-dinosaur animals that lived during the Cretaceous period?

Some non-dinosaur animals that lived during the Cretaceous period include pterosaurs, mosasaurs, ichthyosaurs, ammonites, crocodilians, and various types of mammals and birds.

4. What are pterosaurs?

Pterosaurs were a group of flying reptiles that lived during the Mesozoic era, including the Cretaceous period. They were not dinosaurs, but rather a separate group of animals that evolved the ability to fly independently of birds or bats.

5. What are mosasaurs?

Mosasaurus were a group of large, predatory marine reptiles that lived during the Cretaceous period. They were not dinosaurs, but they were closely related to modern snakes and lizards.

6. What are ichthyosaurs?

Ichthyosaurs were a group of marine reptiles that lived during the Mesozoic era, including the Cretaceous period. They were not dinosaurs, but rather a separate group of animals that evolved a streamlined, fish-like body shape for efficient swimming.

7. What are ammonites?

Ammonites were a group of extinct marine animals that lived during the Mesozoic era, including the Cretaceous period. They were not dinosaurs, but rather a separate group of animals that had a coiled shell and tentacle-like appendages for feeding and locomotion.

8. What are crocodilians?

Crocodilians are a group of reptiles that includes crocodiles, alligators, caimans, and gharials. They have been around since the Mesozoic era, including the Cretaceous period. They were not dinosaurs, but they were closely related to them.

9. What are some mammals that lived during the Cretaceous period?

Some mammals that lived during the Cretaceous period include multituberculates, eutriconodonts, and monotremes. These were all small, primitive mammals that were overshadowed by the much larger dinosaurs.

10. What are some birds that lived during the Cretaceous period?

Some birds that lived during the Cretaceous period include enantiornithes, hesperornithes, and ichthyornithes. These were all groups of birds that had unique features not seen in modern birds, such as teeth or long, spear-like beaks.

11. Why were non-dinosaur animals important during the Cretaceous period?

Non-dinosaur animals were important during the Cretaceous period because they helped to diversify the ecosystem and fill different ecological niches. Without these animals, the world would have been much less diverse and interesting.

12. How do we know about non-dinosaur animals from the Cretaceous period?

We know about non-dinosaur animals from the Cretaceous period through the fossil record. Fossils of these animals have been found in various locations around the world, and scientists have been able to piece together their anatomy, behavior, and ecology from these fossils.