Crocodylomorphs are surviving members of a 230 million-year-old lineage called Crocodylomorphs, a group that contains live crocodiles (i.e. crocodiles, alligators, garials). The crocodile ancestors continued with two mass extinction events: the final mass extinction (2014 million years ago) and the final mass extinction (approximately 66 million years ago). One of the secrets of crocodile longevity is their extremely flexible lifestyle, both in what they eat and in the habitat they get.
Approximately 215 million years ago, it is a land crocodile in what is now northwestern Argentina. Hemiprotostus leali Prepare to eat early mammal relatives Chaliminia musteloides. Image credit: Jorge Gonzalez.
“Many of the groups closely associated with crocodiles exhibited more diverse, more abundant and different ecology, but disappeared except for these few generalist crocodiles who live today,” said Dr. Keegan Melstrom, a researcher at the University of Utah.
“Extinction and survival rate are two aspects of the same coin. Through all mass extinctions, some groups can last and diversify. What can we learn by studying the deeper evolutionary patterns given by these events?”
The Earth has experienced five mass extinctions in its history. Experts claim we are alive throughout the sixth, driven by habitat destruction, invasive species and climate change. Identifying traits that increase survival rates during planetary upheavals could help scientists and conservationists better protect today’s vulnerable species.
Historically, the field has seen mammals as poster children to understand the survival of mass extinction.
Despite their resilience, research has largely ignored alligator clades.
In a new study, Dr. Melstrom and colleagues reconstructed the food ecology of crocodiles and identified the properties that helped several groups to persist and thrive through the final Triassic and mass extinction of the Tododonians.
“There’s a risk that we’ll draw a conclusion millions of years ago and try to apply it directly to conservation. We have to be careful,” said Professor Randy Ilmith at the University of Utah.
“If people study mammals and reptiles and find the same pattern in terms of extinction survival, they may predict that species with a generalist diet will be better.”
“That information helps to make predictions, but it’s rare that you can choose which individual species survive.”
Living crocodiles are famous for being semi-aquatic generalists who thrive in lakes, rivers, and swamps and waiting to ambush unsuspecting prey. Noisy people, they aren’t. Young people enjoy tadpoles, insects, crustaceans and more before graduating to a larger fare, including fish, deer and even fellow crocodiles.
However, today’s crocodile’s uniform lifestyle obscures the massive dietary ecology that crocodiles flourished in the past.
A broader evolutionary group, including early crocodiles and many other extinct strains, Pseudosuchia ruled the land during the late Triassic period (237-2014 million years ago).
Early crocodiles were small to medium-sized creatures, rare in the ecosystem, and were mainly carnivorous animals that ate small animals.
In contrast, other pseudosu bone groups dominated the land, occupying a broad ecological role, exhibiting diverse body types and sizes of vertigo.
Despite their superiority, once a serious extinction hit, the non-crocodylomorph fake su did not survive.
Hypercarnivore crocodile also seemed to die, while generalists on earth went through it.
The authors assume that this ability to eat almost anything allowed them to survive, but many other groups have become extinct.
“Then it becomes a banana. Aquatic high carnivores, terrestrial generalists, terrestrial carbides, terrestrial herbivores – crocodiles have evolved a huge number of ecological roles throughout the age of dinosaurs,” Dr. Melstrom said.
Something happened in the late Cretaceous period and the crocodile faded.
Diverse ecology-focused lineages have begun to disappear even among the generalists on the ground.
Due to the mass extinction event of Cretatuas (separated by meteors that killed non-bird dinosaurs), most of the survivors are semi-predictive generalists and a group of aquatic carnivorous animals.
Nearly all 26 live crocodiles today are semi-rated generalists.
How do scientists analyze food on menus that are millions of years old? They analyze the shape of fossilized teeth and skulls to collect the basics of the animal’s diet.
The author visited museum collections of zoology and paleontology across seven countries and four continents to obtain the necessary fossil specimens.
They examined skulls of 99 extinct alligator species and 20 living crocodile species, creating a fossil dataset that spans 230 million years of evolutionary history.
They previously had built a living database of non-crocodilians, including 89 mammals and 47 lizard species.
The specimens represent a variety of vegetative ecology, ranging from strict carnivorous to mandatory herbivores and a wide variety of skull shapes.
As semiac ambush predators, today’s crocodiles primarily occupy a similar ecological role in many different environments.
They continue to have a very flexible diet. Perhaps it is a remnant of their deep, diverse evolutionary past.
For endangered crocodile people, such as Cuban crocodiles in the Himalayas’ hills and the swamps of the country’s Zapata, dietary flexibility may give us an opportunity to continue our current sixth mass extinction.
The biggest challenges these species face are habitat loss and human hunting.
“I hope that, rather than thinking about ferocious beasts or expensive handbags, when I see living crocodiles and crocodiles, people will appreciate their astonishing 20 million years of evolution and how they survived so many turbulent events in Earth’s history,” Professor Ilmith said.
“Crocodiles are equipped to survive many future changes if they are willing to help maintain their habitat.”
result It will be displayed in the journal Paleontology.
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Keegan M. Melstrom et al. 2025. For a while, Crocodile: Crocodile’s resilience to mass extinction. Paleontology 68(2): E70005; doi: 10.1111/pala.70005
This article is a version of a press release provided by the University of Utah.
