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Unearthed Secrets: Where are Pterosaur Eggs Typically Found?

Pterosaurs were the first recorded vertebrates to have evolved the power of flight. With the ability to fly, we can expect them to reach wide places and travel large distances. The question now will be where they laid their eggs around the place as they traveled. The places where they have their egg can be the way to trace where they migrated or roamed in the past aside from the buried fossils.


Where are Pterosaur eggs found? Pterosaur eggs were found mainly in China and Argentina. A big haul of around 300 Pterosaur eggs was excavated in a marsh in China. These egg specimens have different shell characteristics but show a degree of development in the embryo.

Key Takeaways

  • Pterosaurs were the first vertebrates to evolve flight, with wings formed by skin, muscle, and other tissues, allowing them to travel large distances and hunt near water sources.
  • Most pterosaur eggs have been found in China and Argentina, with a significant discovery of 200 eggs in a Chinese marsh providing valuable insights into their reproduction and development.
  • Pterodactyls, a subset of pterosaurs, laid soft-shell eggs with unique structures that were thin, pliable, and buried in moist ground for incubation.
  • CT scans and X-rays have been used to study pterosaur embryos, suggesting that they could walk but not fly immediately after hatching.
  • Pterosaur nesting behavior was similar to modern birds, laying eggs in a single location and group, as evidenced by fossilized egg remains.
  • Pterosaur discoveries, including eggs and embryos, have been made in Argentina, China, and Italy, shedding light on their evolution, lifestyle, and flying abilities.

Endless discoveries from the world’s vast unexplored lands like fossils from dinosaurs are always fascinating. Today’s scientists and paleontologists have become more curious and have explored many aspects of the Earth’s evolution, including the prehistoric dinosaurs. As we become more curious about dinosaurs’ origin, eggs will come into the story. Dinosaurs are egg-laying, and this is one area with little information. This article will share facts on Pterosaur eggs’ whereabouts and how Pterosaurs lived in the past. 

What Are Pterosaurs?

Pterosaurs were winged reptiles that existed 225-66 million years ago, making them one of the first vertebrates to fly. They had wings formed by a membrane of skin, muscle, and other tissues stretching from their ankles to their fourth finger. Pterodactyls, a type of pterosaur, had an average wingspan of 19.5 inches but some had wingspans of up to 12 meters. Pterosaurs were not dinosaurs but were closely related to them. They were sociable and lived in large colonies. The discovery of well-preserved pterosaur bones in northwest China has greatly boosted our knowledge of these creatures.

What Do We Know About Pterosaur Eggs?

Pterosaurs, a group of extinct flying reptiles that thrived during the Mesozoic era, have long intrigued paleontologists with their unique adaptations and diverse morphology. One aspect that has remained elusive is the nature of their reproductive biology, particularly the characteristics of their eggs.

Recent discoveries of exceptionally preserved pterosaur eggs have provided valuable insights into their structure, composition, and developmental processes. These findings not only shed light on the reproductive strategies of these fascinating creatures but also contribute to our understanding of the evolutionary history of vertebrate reproduction.

Two Places Where Pterosaur Eggs Have Been Found

China – Pterosaur Eggs Found in China

Paleontologists in northwestern China have made a groundbreaking discovery of hundreds of ancient eggs laid by pterosaurs, the flying reptiles that coexisted with dinosaurs. The eggs are believed to have been laid by Hamipterus tianshanensis, a pterosaur species that lived in swampy areas of China in the early Cretaceous Period, about 120 million years ago. The find includes at least 215 eggs in a block of sandstone about 3 meters square, making it one of the biggest hauls scientists have ever found.

The eggs show different stages of Pterosaur embryo, which gave scientists more information on Pterosaur development. The embryos suggest that the animals were able to walk, but not fly, soon after hatching. The nesting behavior of the Pterosaurs is similar to that of modern birds, where they lay eggs at one place and in one group. The eggs were found because of fast-running water causing flooding, which buried the nesting site. (Source)

Argentina – The Pterodaustro Embryo

In 2004, a remarkable discovery was made in Argentina when scientists unearthed a Pterodaustro egg, a unique and fascinating specimen known as MHIN-UNSL-GEO-V246. This elongated, oval-shaped egg measured 6 centimeters in length and 22 millimeters in width, with a soft shell encased in a wafer-thin layer of calcite mineral. A decade later, in 2014, even more astounding eggs from the same species were found, this time preserved in 3D! The Pterodaustro, an ancient flying reptile, has captured the imagination of scientists and enthusiasts alike, drawing comparisons to modern anseriform birds and providing insights into its nocturnal habits and distinctive flying abilities.

Pterodaustro is an ancient flying reptile with fascinating characteristics. The table below presents some of the key findings and observations made by scientists about this intriguing creature.

Pterodaustro FeaturesDescription
Egg DiscoveryIn 2004, a Pterodaustro baby was found inside an egg, called specimen MHIN-UNSL-GEO-V246. The egg was a long oval shape, 6 cm (2.4 inches) long and 22 mm (0.87 inches) wide, with a soft shell covered in a 0.3 mm thick layer of calcite. In 2014, more eggs from the same creature were found, this time preserved in 3D.
Eye BonesScientists compared the eye bones of Pterodaustro to those of modern birds and reptiles, suggesting that this ancient creature might have been active at night, similar to some anseriform birds that love to eat during the nighttime.
Unique Body FeaturesThe Pterodaustro had a long body and neck but short legs, making it a unique flying reptile.

This made it hard for them to take off and fly. Even though they had the same way of launching themselves into the air as other flying reptiles, they needed to do a crazy, low-angle take-off that could only happen in big, open spaces. This is kind of like how geese and swans take off for their flights today. (Source)

Eggshells Of Pterosaurs Found In The United States

There are some documented papers about a pterosaur embryo found in the United States (the Tanis pterosaur) however, it seems to be inconclusive as to whether this is really a pterosaur or not. So currently, we only have the pterosaur eggs found in China and in Argentina, that have been confirmed fossil discoveries of pterosaurs. (Source)

Around 250-300 well-preserved pterosaur eggs were discovered by Xiaolin Wang from the Chinese Academy of Science. It was one of the biggest haul scientists had in the history of their search for fossilized remains. More than the eggs were also embryos discovered with the possibility of more locked away in the ground. 

According to findings, fast-running water causing flooding could have been why the nesting site was buried. The eggs belong to Hamipterus tianshanensis, a pterosaur species that lived in swampy areas of China. These areas are believed to be nesting sites because of the number of eggs found at once. This behavior resembles the nesting behavior of modern birds, where they lay eggs at one place and in one group.

The eggs show different stages of Pterosaur embryo, which gave scientists more information on Pterosaur development. Pterosaur eggs from China and Argentina showed a difference in shell covering, with the former more pliable than Argentina’s find.

Did Pterodactyls Lay Eggs? What Did They Look Like?

Pterodactyls are famous since they are one of the first organisms to develop flight. Similar to other reptiles like dinosaurs, they also lay eggs with structures unique to them.

A Glimpse of Pterodactyls Look and Lifestyle

Pterodactyls belong to the taxonomic order Pterosauria, and they are also winged reptiles. They were identified in 1784 by an Italian scientist Cosimo Collini. Most Pterodactyls were small, but some were massive flying reptiles, including the largest Pterosaurs ever discovered, which had a 12-meter wingspan and stood 3.5 meters tall. Pterodactyls had a wingspan of around 19.5 inches (six meters) on average.

The capacity to fly was one of the Pterodactyls’ distinguishing features, which evolved into powered flight 230 million years ago. Flying allowed pterodactyls to “travel large distances, explore new habitat, elude predators, and swoop down from above to catch their prey.” They flew in the same way that bats and birds do with their forelimbs.

YouTube Video Showing Pterosaur Egg Discovery (2017) in NorthWest China

YouTube video by Science and More describing the pterosaur eggs found and some background on what scientists think about this – AdventureDinosaurs

The pterosaurs had wings formed by a membrane of skin, muscle, and other tissues stretching to their dramatically fourth finger from their ankles. They were coined from the Greek word pteron and sauros, which means “winged lizard.” Neither bats nor birds were close cousins to dinosaurs who evolved separately on the reptile family line or tree branch. They were known to be the first animals after the insects to have the power of flight. They don’t just glide or leap but flap their wings and lift to travel through the air. 

Eudimorphodon and Peteinosaurus are both found in Italian Rhamphorychoids were the first pterosaurs, and their deposits were found in the Late Triassic epoch 200 million years ago. They have wings of about 1 meter or about 3 ft. Their bones were lightweight and flexible, thus strengthened by internal struts that helped them flap their wings. (Source)

Pterosaurs are not dinosaurs; although they had also existed 66 million years ago, they are just closely related to each other through both are archosaurs. They were the first vertebrates to fly and the first reptile to take flight as well. (Source)

Understanding Pterosaur Eggs’ Morphology Through Technology

Pterodactyls do not lay hard-shelled eggs. Instead, they lay soft shell ones, which are buried in the moist abandoned ground. The pterodactyl egg is about 7.2 cm long and is thin and pliable. Their eggs are like snakes and lizards but not brittle ones like birds. Their fossilized eggs, buried on the ground, look like deflated balloons than the eggs we crack for our omelets.

Through the power of technology and its advancements, paleontologists and scientists distinguished what pterodactyls’ eggs looked like and uncovered the way they lay eggs through CT scans and X-rays. They were able to study the microstructure of the bones, which helped them understand how these animals grew or evolved. 

The CT Scans allowed them to have an X-ray to see what is inside the eggs and their embryos without destroying the precious discovery. It was the first one to be done on a pterosaur egg discovery

 Among the 16 embryos, they have found an assortment in the preserved bones, mainly from its wings and bones. Unlike the discovery in Argentina and China, only a few materials from the skull that appeared in the embryos through a single lower jaw were preserved. 

In addition, all of the embryos were incomplete, meaning their bones had been jumbled. As a result, we are still unable to see what they look like until now. Well, at least, we already have a glimpse of how they lived and what they are. And they were able to conclude that the skulls of these types of animals develop later than the other bones in their skeleton. (Source

Despite the incomplete data and pictures, this recent find would add to recent discoveries on Darwinopterus Pterosaur Egg and Caiuajara Pterosaur Egg.

What Places Are Pterosaur Eggs and Other Dinosaur’s Eggs Found?

1. Nesting sites

Pterosaur and other dinosaur eggs have been discovered in various nesting sites around the world. These sites include caves, riverbanks, and floodplains, among others. The eggs are often found in sedimentary rocks, such as sandstone or mudstone, which were deposited in ancient environments conducive to egg-laying. These environments may have been near water sources, such as rivers or lakes, and provided access to food for the developing embryos. Notable discoveries in these nesting sites include the finding of nearly complete pterosaur embryos, which revealed that hatchlings may have required parental care for feeding. Additionally, ongoing research at these sites aims to understand the range of egg sizes and shapes and the variation in animal size.

2. Fossil remains

The first pterosaur egg fossils were discovered in the early 2000s. Paleontologists discovered these eggs in China and Argentina. These eggs were preserved in sediments, which helped to protect them from damage. Fossil remains of pterosaur eggs are discovered through a process called excavation. This process involves carefully removing the sediment surrounding the egg to avoid damaging the fossil.

Once the egg has been excavated, it is taken to a lab for further study. Scientists can use a variety of techniques to analyze the egg, such as CT scans and chemical analysis. These techniques can provide information about the egg’s size, shape, and composition. The significance of these discoveries is that they provide insight into the reproductive behavior of pterosaurs.

By studying the eggs, scientists can learn about the size and shape of the eggs, which can provide clues about the size and behavior of the parent pterosaurs. Overall, the discovery of pterosaur egg fossils is an important step in understanding the behavior and evolution of these ancient creatures.

3. Lake sediments

In 2017, paleontologists discovered pterosaur eggs in lake sediments in China. The eggs were identified as belonging to the species Hamipterus tianshanensis, which had a wingspan of up to 13 feet and lived during the Late Jurassic period. The discovery of the eggs provided important insights into the reproductive behavior of pterosaurs. The eggs were elongated and soft-shelled, suggesting that they were buried in sediment rather than being laid in nests. This discovery also provided evidence that pterosaurs were able to fly shortly after hatching, as the eggs were found in a location that would have been difficult for non-flying animals to access.

4. Sandstone Blocks

Pterosaur eggs and other dinosaur eggs have been discovered in sandstone blocks, providing valuable information about the history of life on Earth. The following table outlines the importance of sandstone blocks in preserving fossils and the techniques used to extract eggs from these blocks.

Sandstone Blocks in Fossil PreservationTechniques for Extracting Eggs from Sandstone Blocks
Sandstone is a sedimentary rock that forms from the accumulation of sand grains, creating a porous structure suitable for fossil preservation.Researchers use a combination of traditional paleontological techniques and modern technology to carefully chip away at the rock without damaging the fossils inside.
Minerals in the sand seep into the bones and other remains when fossils are buried, gradually replacing them and creating a fossilized replica.Once the eggs are exposed, CT scans and other imaging techniques are used to study the contents without having to break them open.
Sandstone blocks can contain multiple layers, each corresponding to a different period in time, providing a wealth of information about the history of life on Earth.The discovery of 215 pterosaur eggs in a single sandstone block in China was a major breakthrough, offering unprecedented insight into the reproduction and behavior of these flying reptiles.

5. Fossil Excavation Sites

Pterosaur and dinosaur eggs have been found in various fossil excavation sites around the world. One such site is the Dinosaur Provincial Park in Alberta, Canada. This site has been a rich source of dinosaur fossils since the early 1900s, with over 40 different species of dinosaurs discovered to date. In 1987, pterosaur eggs were discovered at the park, making it one of the first sites where pterosaur eggs were found.

Another notable site is the Gobi Desert in Mongolia, which is known for its vast deposits of dinosaur fossils. In 1993, a team of researchers discovered the first known fossilized dinosaur eggs in the Gobi Desert. Since then, numerous dinosaur eggs have been found at the site, including those belonging to theropods, sauropods, and ornithopods.

The Yixian Formation in China is another important fossil excavation site. This site is known for its exceptionally well-preserved fossils, including those of pterosaurs, birds, and dinosaurs. In 2004, researchers discovered the first pterosaur eggs at the Yixian Formation, providing new insights into the reproductive biology of these ancient creatures.

The article you are reading is one of the 11 Series Articles connected to the Flying Dinosaur Types – Ultimate Guide to Pterodactyls, Pterosaurs. Check out the Ultimate Guide (see description and link directly below) or other key Series Articles selected for you at the bottom of this article!

Flying Dinosaur Types – Ultimate Guide to Pterodactyls, Pterosaurs
Main Article – With Links to 11 Series Articles


❖ Read Now! Flying Dinosaur Types – Ultimate Guide to Pterodactyls, Pterosaurs

This is the main article in the series and it is packed with information all about the flying reptiles that ruled the skies during the Mesozoic Era. It covers the different types of pterosaurs, from the basal pterosaurs and later species as well. There are sections on pterodactyl anatomy, classification, and phylogeny. The master article also covers:

—Interesting facts you may not know about pterosaurs
—Tables comparing wingspan sizes of different pterosaur species
—Links to all the Series Articles (11 in total!) which give deeper information about the pterosaurs

Where Did Pterodactyls Live? Did Pterodactyls Live in Caves?

The journey of Pterosaurs in many areas means that they have made a stop-over along the way. With many choices in the landscape, they may have chosen a cave as a pit-stop or shelter, also considering good access to food.

Pterodactyls Preferred Habitats and Fossil Implications

Pterodactyls have lived in trees. They have awkward sprawling posture, but they have strong claws, which makes them excellent climbers. Basal Pterosaurs were insectivores or known to be predators of small vertebrates.

They usually live near the sea or waters where they hunted food, and one proof here is the large haul of pterosaur eggs excavated in a wetland area during the Cretaceous period. The presence of eggs in Argentina and China indicates that adults, of course, have lived in these areas. (Source)

Cave as One of Its Shelters

Pterodactyls appear to form big groups, similar to certain modern birds, and their behavior should have been as diverse as that of today’s bird species. Pterosaurs have also been discovered in caves. They resided in various parts of the United States, Guam, China, Japan, England, Germany, France, Tanzania (Africa), and various other locations. (Source)

They may have fed on insects and smaller vertebrates in the caves they use for shelter as meat-eaters. Some fossils are found in caves that are proof of caves as one of their shelters.

Frequently Asked Questions

What Are Pterosaur Eggs?

Pterosaur eggs are extremely rare fossils that have been discovered in limited numbers. Pterosaurs were an order of flying reptiles that lived around 66 million years ago and were not dinosaurs but went extinct at the same time. Only a few pterosaur egg fossils have been unearthed, and of those, only six are three-dimensional. However, a recent discovery in China’s Turpan-Hami Basin has yielded 215 three-dimensional pterosaur eggs, some of which still contain the remains of embryos.

The eggs are pliable and beautifully preserved and have provided paleontologists with an embarrassment of riches in terms of information about how pterosaurs progressed from egg to adult. The eggs were buried in the sand and vegetation found on the shores of lakes or rivers.

Where Are Pterosaur Eggs Typically Found?

Pterosaur eggs are rare and were not discovered until the early 2000s. Since then, only a few dozen have been found. The majority of pterosaur eggs have been discovered in China and Argentina. A significant discovery was made in northwestern China, where around 250-300 well-preserved pterosaur eggs were excavated by Xiaolin Wang from the Chinese Academy of Science.

The eggs belonged to Hamipterus tianshanensis, a pterosaur species that lived in swampy areas of China. These areas are believed to be nesting sites because of the number of eggs found at once. The eggs show different stages of Pterosaur embryo, which gave scientists more information on Pterosaur development. The discovery of pterosaur eggs illuminates how the winged reptiles bred and how their babies may have behaved.

Are Pterosaur Eggs Fossilized?

Yes, pterosaur eggs can be fossilized. In fact, a recent discovery in northwestern China yielded 215 pterosaur eggs, 16 of which still had embryos inside. These eggs provide important insights into how pterosaurs laid their eggs, how they developed, and even how pterosaur parents cared for their young. The eggs were found in a block of fossilized sandstone and were confirmed to be soft-shell, similar to the eggs of today’s lizards and some turtles. This suggests that pterosaurs likely buried their eggs instead of incubating them like birds.

How Are Pterosaur Eggs Identified?

Pterosaur eggs are identified by their unique characteristics, including their shape, size, and texture. These eggs are typically elongated and pointed at one end, similar to a football. They are also relatively small, with a length ranging from 3 to 7 centimeters. The texture of the eggshell is smooth and thin, with a calcareous composition that allows for preservation over millions of years.

Pterosaur eggs are also grouped in clusters, which suggests that these animals may have laid their eggs in communal nests. The discovery of hundreds of pterosaur eggs in northwestern China has provided valuable insight into the reproductive behaviors of these ancient creatures. By studying the embryos within the eggs, scientists have been able to determine that hatchlings could walk but not yet fly, and may have required some parental care for feeding.

How Do Pterosaur Eggs Compare to Lizard Eggs?

Pterosaurs lay soft-shelled eggs, unlike lizards which lay hard-shelled eggs. Pterosaur eggs are thin and pliable, measuring about 7.2 cm long, and are buried in moist abandoned ground. Their eggs are not brittle like bird eggs and look like deflated balloons. CT scans and X-rays have helped scientists study the microstructure of the bones and understand how these animals grew or evolved. The recent discovery of 215 pterosaur eggs, 16 of which still have embryos inside, confirmed that pterosaurs laid soft-shell eggs like lizards, rather than hard-shell eggs like birds.


The presence of Pterosaur eggs in few places on the planet means that they roamed in this area. Though, there might be a missing link of how they were distributed throughout the world. Fossilized bones and egg remains are just a few of the specimens that gave us a different view of Pterosaurs‘ lifestyle, reproduction, growth, and development. These findings are comparable to modern-day animals. Hence it is a piece of important information to look at the world from a different perspective.