Mary Anning fossils: Seven highlights from the Jurassic Coast

Mary Anning (1799–1847) was a pioneering palaeontologist who collected and sold fossils that she found near her hometown of Lyme Regis on England’s Jurassic Coast. This area is renowned for the incredible diversity of prehistoric life preserved within its rocks.

Mary worked with eminent scientists of her time and her fossils continue to be hugely important for how we understand marine life in the Jurassic Period.

Here are seven fascinating fossils acquired from Mary that are now part of palaeontology collections we look after.

1. Temnodontosaurus

When she was 12, Mary’s older brother Joseph discovered an enormous, strange-looking skull on the beach between the town of Lyme Regis and village of Charmouth. About a year later, in 1812, Mary took on the task of painstakingly uncovering the rest of what turned out to be a five-metre-long ancient marine reptile. This incredible discovery kicked off her career as a fossil collector.

Initially named Ichthyosaurus platyodon, Mary’s specimen was the first largely complete ichthyosaur to be uncovered and scientifically described. However, as scientists began to realise just how many different species of ichthyosaur there once were, Mary’s discovery was renamed Temnodontosaurus platyodon. It lived in the Early Jurassic Period, around 200 million years ago.

Henry Hoste Henley, Lord of the Manor of Colway, bought the ichthyosaur skeleton from Mary and it was later displayed in London. This precious specimen was eventually sold again and is now part of the collections we care for.

You can see parts of it, including the skull, on display in our Fossil Marine Reptiles Gallery. At the moment, you can also touch a cast of the skull in our exhibition Jurassic Oceans: Monsters of the Deep.

2. Plesiosaurus dolichodeirus

The walls of our Fossil Marine Reptiles Gallery are lined with the skeletons of fascinating sea creatures that once ruled Earth’s oceans. Among them is another of Mary Anning’s greatest finds – Plesiosaurus dolichodeirus. Not only is it a near-complete skeleton, it’s also articulated, meaning that the bones are connected together in their natural, anatomical positions.

Like ichthyosaurs, plesiosaurs were ancient marine reptiles. They first appeared in the Triassic Period and went extinct at the end of the Cretaceous Period – like the dinosaurs, their fate was sealed by an asteroid that crash-landed in Mexico 66 million years ago.

An unmissable feature of Plesiosaurus dolichodeirus is its long neck, which is roughly the same length as its body and tail combined. Mary’s specimen is the holotype – the specimen to which all others are compared to. It was used by palaeontologist William Conybeare as the basis for this new reptile’s name – in Greek ‘dolichos’ means long and ‘deire’ means neck. Some plesiosaurs, such as this one, had small heads with extremely long necks. Others had short necks with massive jaws and teeth instead.

Plesiosaurus dolichodeirus was such a strange reptile that, initially, respected French naturalist Georges Cuvier disputed the find, thinking it was a fake, a mistake or two different animals put together – known as a composite. However, he was eventually convinced and sent someone to Lyme Regis to purchase a specimen for the Muséum National d’Histoire Naturelle in Paris. Ever the businesswoman, Mary bought a specimen from another collector and then sold it to Georges for three times the price.

The importance of the discovery of Plesiosaurus dolichodeirus can’t be understated. At the time, it was arguably more important than dinosaurs in helping to convince people that our planet is incredibly old and that animals can go extinct.

3. Hybodus

While the fossils Mary found are crucial to our understanding of prehistoric worlds, she never published any scientific papers on them herself.

In fact, as far as we know, Mary’s only published work appears in an edition of the Magazine of Natural History in 1839. It’s a brief extract from a letter sent to the editor Edward Charlesworth, offering a correction on his description of a fossil fish called Hybodus delabechei. In it she mentions a conversation she’d had about similar fossils with famous biologist Louis Agassiz. However, despite Mary’s knowledge and experience, Edward’s response to her letter is dismissive and suggested she was mistaken.

Hybodus species were sharks that grew to between two and three metres in length and belonged to a group known as Hybodontiformes. They had two defensive spines on their dorsal fins and a combination of sharp, clasping teeth and flatter teeth for crushing shelled prey.

Today, Hybodus is considered a ‘wastebasket taxon’. This is essentially a catch-all collection of animals that don’t fit neatly into other taxonomic groups and need to be reassessed by scientists. Many Hybodus species have been named from isolated teeth or fin spines with a wide range of physical characteristics and from a broad range of time. It’s not just fish where this lumping together of species has happened. The dinosaur genus Iguanodon, for example, was a wastebasket taxon until some species were reassigned to different genera, such as Mantellisaurus.

4. Palaeocoma milleri

This fossil might look like a starfish, but it’s actually a closely related animal called a brittle star. They’re named after their very brittle arms, which easily break off when handled or attacked by predators. There are around 2,000 brittle star species living in the oceans today, but their story goes all the way back to the Ordovician Period, around 480 million years ago.

This specimen of Palaeocoma milleri in the collections we care for was one of three brittle stars bought from Mary in 1840. It was originally thought to be Ophiura egertoni. However, we now know it to be the species Palaeocoma milleri.

Palaeocoma brittle stars lived approximately 240 to 180 million years ago, from the Middle Triassic to the Early Jurassic.

5. Ichthyosaurus anningae

When new animals are discovered, scientists sometimes choose to name them after someone significant or famous. For example, displayed in our Fossil Marine Reptiles Gallery is Attenborosaurus conybeari, named after both broadcaster Sir David Attenborough and palaeontologist William Conybeare.

Mary has several species named after her, although only one was named during her lifetime – the prehistoric fish Acrodus anningiae. There are now reptiles, bivalves and ostracods named in her honour too, as well as a research vessel owned by Swansea University.

A recent renaming has added another to the list – the ichthyosaur Ichthyosaurus anningae. We house a specimen of this species in the collections, but it was originally incorrectly identified as Ichthyosaurus communis. In 2015, however, a study proposed that it could actually be an example of a new species named after Mary.

The specimen collected by Mary is a nearly complete, articulated skeleton. We can also see coprolites – fossilised poo – inside its ribcage. Mary was among the first to study coprolites, finding the remains of fish scales and bones inside them, helping other scientists figure out what these strange fossils were. Coprolites can tell us about the diet of prehistoric creatures and therefore the environments they were living in.

6. Coleia antiqua

This specimen of Coleia antiqua is thought to be the only arthropod in the collection we care for that was collected by Mary Anning.

Arthropods are a truly ancient group of animals, first appearing in the Cambrian Period, which lasted from 539 million to 485 million years ago. We categorise arthropods as having segmented bodies, tough exoskeletons and jointed appendages. They include prehistoric icons such as trilobites as well as all insects, arachnids and crustaceans.

Coleia antiqua was a decapod crustacean – the group of 10-legged creatures that includes crabs, lobsters and prawns.

The animals in this genus lived between the Late Triassic and Late Jurassic periods. They’re part of a group of decapods known as Polychelida, so they still have a few living relatives, such as the prawn- or squat lobster-like Stereomastis sculpta.

We didn’t buy this Coleia antiqua specimen directly from Mary. She sold it to the Viscount William Willoughby Cole, Third Earl of Enniskillen. Towards the end of his life in 1882, his collection of almost 10,000 specimens was sold to us, just a year after our building in South Kensington opened to the public.

The specimen is another holotype.

7. Dimorphodon macronyx

Mary may be famous for her marine reptile finds, but did you know that she discovered a flying reptile too?

Before the 1820s, the only pterosaurs that had been discovered had been found in Germany. That was until Mary found one in the rocks near Lyme Regis. Even though it wasn’t a complete specimen, it was an incredibly exciting find.

In his paper discussing Mary’s discovery, palaeontologist William Buckland colourfully describes pterosaurs as monsters “resembling nothing that has ever been seen or heard-of upon earth, excepting the dragons of romance and heraldry”.

He named Mary’s specimen Pterodactylus macronyx, with macronyx referring to its particularly long claws. The specimen was later assigned to a new genus, Dimorphodon. This name refers to the two types of teeth in this pterosaur’s jaws – although we don’t see them in Mary’s specimen as it lacks a skull.

Although often confused with dinosaurs, pterosaurs were a distinct group of flying reptiles. Their wings were large membranes of skin that stretched from their arms and elongated little fingers down to their ankles.

Some pterosaur species were huge – some were even as tall as a giraffe! Dimorphodon was on the smaller side, roughly around a metre in length with a wingspan of up to two metres. It probably lived along the coast and likely dined on small vertebrates.

Mary’s Dimorphodon is on display on the first-floor balcony of our Hintze Hall.