What is the ancestor of sea turtles?
These turtles were far more common than previously known. Paleontologists have found a new sea turtle species from the Cretaceous epoch which they believe to be an ancestor of all modern turtles. This is a reconstruction of the new species ( Peritresius martini ). Image credits: Drew Gentry.
Are turtles related to dinosaurs?
The earliest turtles existed together with the dinosaurs millions of years ago. However, the connection to dinosaurs is somewhat distant and is considered to be closer to birds and crocodiles, than for instance, lizards and snakes. Descendants of ancient turtles are still present today, with most of them being species of sea turtles.
Where did turtles come from?
The First Turtles Paleontologists still haven't identified the exact family of prehistoric reptiles that spawned modern turtles and tortoises, but they do know one thing: it wasn't the placodonts.
Are turtles primitive reptiles?
Believed to have been around a long time ago, turtles are among the oldest and most primitive reptiles today. Scientists claim that ancient turtles lived along with dinosaurs approximately 110 million years ago, until the K-Pg extinction event, which wiped out the dinosaurs.
Are turtles ancestors of birds?
They may not be kissing cousins, but new DNA analysis confirms that turtles share ancestry with birds and crocodiles, according to a recent paper co-authored by an Occidental College biologist.
Do turtles and humans have a common ancestor?
Humans and turtles share a common ancestor What is remarkable is that the basic organisation of the EDC genes is similar in humans and turtles. This leads to the conclusion that the prototypical EDC genes developed in a common ancestor, who lived 310 million years ago and was similar to modern reptiles.
When did turtles first evolve?
around 230 million years agoThe origin of turtles Turtles are known to have originated around 230 million years ago during the Triassic Period, but what exactly they evolved from is still debated.
How much DNA do humans share with turtles?
Giant tortoises and humans share more than 90 per cent of their DNA, but Professor Beheregaray said it was the differences that made the comparison interesting.
What are turtles related to?
The researchers found that turtles are most closely related to crocodiles, and least similar to snakes and lizards.
Did turtles exist before dinosaurs?
Did Tortoises Live With Dinosaurs? Turtles pre-date dinosaurs as they came into being 250 million years earlier. Dinosaurs and tortoises lived together for millions of years, sometimes even in the same environments.
What was the first animal on Earth?
comb jellyEarth's first animal was the ocean-drifting comb jelly, not the simple sponge, according to a new find that has shocked scientists who didn't imagine the earliest critter could be so complex. The mystery of the first animal denizen of the planet can only be inferred from fossils and by studying related animals today.
Where did the turtle originate from?
The story of all turtles actually begins here, in South Africa – although in a very different world. About 260 million years ago, on the shores of the ancient Karoo sea, among dunes and shrubs of a semi-arid Gondwana, lived a small reptile called Eunotosaurus africanus. Eunotosaurus africanus. Image source: Wikimedia.
How are humans and turtles similar?
Things that are similar about turtles to humans We are both vertebrates. Both turtles and humans have a endoskeleton. A endoskeleton is a skeleton on the inside as a exoskeleton is on the outside. They are designed the same way because humans and turtles both have a back bone also have two legs and two arms.
Which is the direct ancestor of turtle?
Eunotosaurus africanus, the earliest known turtle, lived 260 million years ago. Eunotosaurus was toothed, and its midsection contained nine elongated trunk vertebrae, nine pairs of broad T-shaped dorsal ribs, and five pairs of gastralia (ventrally located abdominal ribs).
What is the common ancestor of mammals and turtles?
Within a few million years, two important amniote lineages became distinct: synapsids, from which mammals are descended, and sauropsids, from which lizards, snakes, turtles/tortoises, crocodilians, dinosaurs, and birds are descended.
Which of the following is direct ancestor of turtle?
Hence, the correct answer is 'Chelonia'
What is the evolutionary origin of turtles?
The evolutionary origin of turtles has been called one of the great unanswered questions of evolutionary biology. The scientific community does not know from what group of primitive reptiles’ turtles descended.
When were turtles first found?
The oldest marine turtle fossils found date from the Jurassic period (208 to 145 million years ago). By that time, the main lineage of turtles had split into two branches: the side-neck turtles (pleurodires), which protect the head by folding the neck and head over to one side, and the hidden-neck or arch-neck turtles (cryptodires), which pull the neck into a vertical S-curve and retract the head straight back between the shoulders. The side-necked turtles produced many seagoing species during the Cretaceous period (145 to 65 million years ago), but these died out. Modern pleurodires live in freshwater. Jurassic sea turtles belonged to the hidden-neck group, the group to which more turtles belong today. Many families once made up the hidden-neck group, but most died out by the early part of the Cretaceous period.
What are the extinct Protostegidae?
The extinct Protostegidae may be related to the Dermochelyidae. Like the toxochelyids, many of the protestegids had frame-type shells with gaps between the bones, and probably lived in open ocean. Although later protostegids were large to gigantic sea turtles with vast heads, the earliest known protostegid, Santanachelys, from 110 million years ago, was only 20 cm (8 inches) long. Like modern fresh-water turtles, Santanachelys had highly flexible flippers with movable digits, but, like marine-dwelling turtles, it also had large salt-excreting glands, showing that it lived in the ocean. Later, protostegids had semi-rigid flippers like modern sea turtles. This family includes the giants Protostega and Archelon, the latter being the largest sea turtle that ever lived.
What are the names of the two families of hidden neck sea turtles?
Four important families of hidden-neck sea turtles survived into the mid-Cretaceous period. Two of these families, the Dermochelyidae and the Cheloniidae, have modern descendants. The leather-back sea turtle is the only surviving member of the Dermochelyidae. All other modern sea turtles belong to the Cheloniidae.
How big can a sea turtle grow?
The giant sea turtle Protostega, from the late Cretaceous period (80 to 70 millionyears ago), could grow as long as 4.2m (14 feet). Most modern turtles have a solid bone layer in the carapace, but Protostega, like Toxochelys, had large gaps between the bones, which reduced the turtle’s weight, possibly giving it an advantage in open sea habitat.
How much did the Archelon turtle weigh?
Archelon, the largest sea turtle that ever lived (about 75 million years ago) and may have weighed between two to five tons.
When did the protostegid turtles disappear?
Many types of ammonites occupied the seas during most of the Mesozoic era, but they disappeared toward the end of the Cretaceous period. This may explain why the protostegid turtles disappeared at about the same time. Only one species of protostegid has survived the mass extinction that eliminated the dinosaurs and the last of the giant fishlike reptiles at the end of the Cretaceous period. Eventually it too disappeared, leaving the leatherback and cheloniid lines (and a variety of terrestrial and freshwater turtles) to carry on to modern times.
Where are turtle fossils found?
Turtle fossils in the Triassic are rare, but by the end of the Triassic they occur globally. The oldest goes back to the Middle Triassic, just before the earliest dinosaurs. Among the best known, from the Late Triassic, is Proganochelys, found in Thailand and in several parts of Germany, where the sedimentary clues suggest a brackish or marginal marine environment. The turtle may have been washed down to its resting place by coastal rivers. Its forelimb dimensions and heavy armour point to a terrestrial existence (Joyce & Gauthier 2003), but the ratio of the width of carapace (dorsal shell) to plastron (bony underbelly) suggest it was aquatic (Lichtig & Lucas 2017). It had toed feet, teeth on the palate (but not on the jaws), a spiky neck with ribs, and a club-like tail. If the tail was used for defence, it would have had little effect in water. The teeth hinted at an ancestry among non-turtles (modern turtles do not have teeth).
Where did the tortoises come from?
The oldest tortoise fossils come from the late Palaeocene of Mongolia. By then the transition back to the land, at least in one lineage, was already complete. In the Eocene, tortoises colonised North America, Europe and Africa and adapted to an immense range of environments, from forests to deserts.
What is the habitat of Odontochelys?
The habitat of Odontochelys was probably river delta or shallow marine. Eorhynchochelys was found at the same site 7.5 m lower in the rocks and was thus slightly older. It had neither carapace nor plastron, and had a long tail. On the other hand, it had a beak (an advanced feature) and lacked teeth.
Why is the turtle phylogeny unsolved?
This phylogenetic problem has remained unsolved partly because turtles have such a unique morphology that only few characters can be used to link them with any other group of amniotes. (Zardoya & Meyer 2001)
How many genera are there in the leatherback turtle family?
Today sea turtles are much less diverse than in prehistoric times: just two families and six genera. The leatherback is a family all by itself.
How long does it take for a turtle to hatch?
She will never know her infants. She repeats the burial ritual several times in the course of the nesting season. In about two months , that first clutch will hatch, and over a few days the newborn turtles will dig their way to the surface. Like their unseen mothers, they know what to do by instinct.
Do sea turtles have natural selection?
Even today, sea turtles must draw their oxygen from the air and come ashore to lay their eggs. Whatever its powers, natural selection has not delivered them from these handicaps. And surely it must be a handicap that so few progeny make it to adulthood (perhaps 1 in 1000).
What is the evolution of turtles that weren't?
Turtles That Weren't: Placodonts of the Triassic Period. Before discussing the evolution of genuine turtles, it's important to say a few words about convergent evolution: the tendency of creatures that inhabit roughly the same ecosystems to develop roughly the same body plans.
When did turtles evolve?
In a way, turtle evolution is an easy story to follow: the basic turtle body plan arose very early in the history of life (during the late Triassic period ), and has persisted pretty much unchanged down to the present day, with the usual variations in size, habitat, and ornamentation.
How long did Odontochelys live?
Unfortunately, only a few weeks later, Chinese paleontologists announced the discovery of Odontochelys, which lived a whopping 50 million years earlier. Crucially, this soft-shelled marine turtle possessed a full set of teeth, which subsequent turtles gradually shed over tens of millions of years of evolution.
What is a one ton tortoise?
The one-ton, southern Asian Colossochelys (formerly classified as a species of Testudo) can pretty much be described as a plus-sized Galapagos tortoise , while the slightly smaller Meiolania from Australia improved on the basic turtle body plan with a spiked tail and a huge, weirdly armored head.
What reptiles spawned tortoises?
Paleontologists still haven't identified the exact family of prehistoric reptiles that spawned modern turtles and tortoises, but they do know one thing: it wasn't the placodonts. Lately, the bulk of the evidence points to an ancestral role for Eunotosaurus, a late Permian reptile whose wide, elongated ribs curved over its back (a striking adumbration of the hard shells of later turtles). Eunotosaurus itself seems to have been a pareiasaur, an obscure family of ancient reptiles the most notable member of which was the (completely unshelled) Scutosaurus.
How long has it taken for turtles to reach the Pleistocene?
You have to fast-forward about 60 million years, to the Pleistocene epoch, to find prehistoric turtles that approached the size of this duo (this doesn't mean that giant turtles weren't around in the intervening years, just that we haven't found much evidence).
How big were the turtles in the Cretaceous?
The most notable turtles of the Cretaceous period were a pair of marine giants, Archelon and Protostega, both measuring about 10 feet long from head to tail and weighing about two tons.
What era did sea turtles originate?
Paleontologists have found a new sea turtle species from the Cretaceous epoch which they believe to be an ancestor of all modern turtles.
How long have turtles been around?
If you look at turtles today, it’s easy to guess that they’ve been around for a very long time. Like crocodiles and other reptiles, they had ancestors that lived alongside the dinosaurs in the Mesozoic times. Such an ancestor was Peritresius ornatus, who lived in North America during the Late Cretaceous epoch — from around 100 to 66 million years ago. Researchers thought that P. ornatus was the sole member of its group but now, a new study has found a sister species.
Is the turtle clade widespread?
The finding also shows that turtles belonging to this clade were far more widespread than previously believed. It’s unclear if other species belonging to the group existed.
How long have turtles been around?
The remaining two families (the Cheloniidae, or hard-shelled turtles, and the Dermochelidae, or leathery turtles) are the remnants of the many species of marine turtles that descended from a common ancestor about 95 million years ago .
How long ago did sea turtles first appear?
The time scale below depicts when those forms arose, based upon fossil evidence. The modern sea turtles arose from a common ancestor about 110 million years ago and gave rise to 4 families of marine turtles.
How many times have species gone extinct?
extinctions” in which ~ 75% of all species suddenly go extinct, have occurred at least 5 times at roughly 26 million year intervals back in time. What caused these rather sudden events? Current thinking is that meteor strikes and large scale volcanic eruptions may have been involved and temporarily changed the physical and chemical environment on earth so radically that most organisms were unable to survive. Regardless of the cause (s), however, the consequences were much the same. The survivors suddenly found themselves in a world without competitors, and so what followed was an explosion of new species that exploited the habitats formally occupied by the extinct forms.
How much of the species that existed in the past no longer exist?
In fact, well over 95 % of all the species that existed in the past no longer exist, and have been replaced by new species. It’s also important to realize that natural selection isn’t the only force that influences which species persist and which disappear. There is good evidence that chance events also may play a role.
How does evolution occur?
Recall that biological evolution is defined as descent (from a common ancestor) accompanied by modification. That definition incorporates two key concepts. The first is that all life evolved once on this planet and so can be traced back to ancestral forms. The second is that over time, newer kinds of living creatures have been produced by changes (“modifications”) of the older kinds. Modification occurs because, as Darwin pointed out some years ago, (i) all kinds of organisms (We call them “species”.) produce more offspring than can possibly survive, (ii) those offspring vary in their appearance, physiology and behavior, and (iii) some of those variants are better able to survive than others. Thus, over succeeding generations, the appearance of organisms changes as the competitively superior individuals replace those that are less able to compete. Darwin called this process “natural selection”. Repeat this generation after generation, over many thousands or even millions of years, and the result is the creation of new species. Each of these can be considered an experiment that is either successful (as witnessed by the proliferation of other, similar species)
What happens to all the species that have existed in the past?
But there is no arguing about one consequence: all species eventually go extinct. Museum drawers are full of the fossils of plants and animals that had “their day in the sun”, and no longer exist. In fact, well over 95 % of all the species that existed in the past no longer exist, and have been replaced by new species.
What animals survived the extinction event?
The mammals, for example, diversified to occupy many of the habitats formally occupied by the reptiles, and so did the extant birds, which fossil and anatomical evidence indicate are dinosaurs that survived the extinction event that doomed their close relatives. One final detail should be mentioned.
How old are sea turtles?
The oldest sea turtle fossils are about 140 million years old. It is around the time when dinosaurs lived on Earth. Ancient turtles like Protostega and Archelon lived during the Late Cretaceous (65 million years ago). Archelon is the largest turtle fossil reaching a length of 15 feet and estimated to weigh 4,900 lbs.
Where are sea turtles found?
The Archelon fossils were found in South Dakota in 1895. Other sea turtle fossils have been found in South America, Middle East, China, and Australia.
What is the formal name for a turtle?
In the 1950s, Testudines became the formal name for turtles. Testudines are under the clade Archelosauria, but in terms of taxonomy, Order Testudines are under the Class Reptilia. Dinosaurs are also under Class Reptilia. Like all reptiles, turtles lay eggs.
How long can a Galapagos turtle live without eating?
An observation of Galapagos turtles shows that they have a slow metabolism and survive for days without eating. A similar ability with this, plus having a protective shell structure, could have helped ancient turtles survive the K-Pg extinction faced by other prehistoric reptiles.
What suborder is the turtle?
At the same time, Suborder Pleurodira includes the snake-necked, side-necked, and big-headed turtles, which total 93 species in 3 families. Succeeding classifications after the suborders are based on differences in the modern turtles’ skull and shell.
Where was the Therizinosaurus found?
The Therizinosaurus was a theropod dinosaur whose fossils were found in the Gobi desert, had giant claws, and was hunchbacked. Initially, paleontologists thought they found an ancient turtle fossil – AdventureDinosaurs
Where were Therizinosaurus fossils discovered?
When the Therizinosaurus fossils were first discovered in Mongolia, it was thought to be a turtle. In 1954, a Russian paleontologist claimed that the fossils resemble a modern sea turtle. It led to an assumption that the Therizinosaurus fossils were fossils of ancient turtles.
