Stay up to date with notifications from The Independent

Notifications can be managed in browser preferences.

New dinosaur discovery may explain why T-rex had small arms

T-rex likely carried out many tasks with its mouth to compensate for tiny limbs

Sravasti Dasgupta
Friday 08 July 2022 11:42 BST
Comments
(RELATED) Newly-discovered dinosaur: T-Rex’s tiny cousin

Your support helps us to tell the story

From reproductive rights to climate change to Big Tech, The Independent is on the ground when the story is developing. Whether it's investigating the financials of Elon Musk's pro-Trump PAC or producing our latest documentary, 'The A Word', which shines a light on the American women fighting for reproductive rights, we know how important it is to parse out the facts from the messaging.

At such a critical moment in US history, we need reporters on the ground. Your donation allows us to keep sending journalists to speak to both sides of the story.

The Independent is trusted by Americans across the entire political spectrum. And unlike many other quality news outlets, we choose not to lock Americans out of our reporting and analysis with paywalls. We believe quality journalism should be available to everyone, paid for by those who can afford it.

Your support makes all the difference.

Scientists in Argentina have found a new giant predatory dinosaur which maye help explain the mystery behind why Tyrannosaurus rex has such short arms.

Scientists writing in the Current Biology journal said that extensive skeletal remains of the previously unknown species were dug up in Patagonia.

Named Meraxes gigas, the species were about 36ft (11m) long, with a 1.2m skull and arms that were only 60cm long.

In contrast, T-rex was around 13m (45 foot) long and may have had a skull 1.5m (5ft) long, but arms only about 1m long.

The species found by the scientists has been named Meraxes after a dragon of the Song of Ice and Fire fiction series by George RR Martin and gigas, Greek for giant, referring to the enormous size of the species.

Juan Canale, lead author of the study said to BBC: “I’m convinced that those proportionally tiny arms had some sort of function. The skeleton shows large muscle insertions and fully developed pectoral girdles, so the arm had strong muscles.”

“They may have used the arms for reproductive behaviour such as holding the female during mating or support themselves to stand back up after a break or a fall.”

The study has been co-authored by Mr Canale and Peter Makovicky.

Mr Makovicky said that the dinosaur’s arms were “literally half the length of the skull and the animal would not have been able to reach its mouth”.

The scientists believe that the species’ massive heads were the main predatory tool and performed functions that arms would have had in smaller species.

They added that two other species - tyrannosaurids and abelisaurids - also developed small arms for similar reasons.

A study in April had suggested that the arms of T rex likely shrank in length as an adaptation to prevent amputations when a pack of the mighty dinosaurs descended on carcasses with their massive heads and bone-crushing teeth.

Join our commenting forum

Join thought-provoking conversations, follow other Independent readers and see their replies

Comments

Thank you for registering

Please refresh the page or navigate to another page on the site to be automatically logged inPlease refresh your browser to be logged in