speed of spinosaurid dinosaur teeth replacement accounts for their overabundance in cretaceous sites
Reconstruction of the skull of a spinosaurid dinosaur. Coloured the place where the fossil should be. Scale: 25 cm. Erik Isasmendi. Credit: UPV/EHU

Spinosaurid dinosaurs were able to develop up to three generations of teeth at the same time, a high replacement rate that explains why so many teeth of this type have been found in Cretaceous sites. This has been confirmed by a study in which researchers from the UPV/EHU are taking part and which has been published in the journal Historical Biology.

The article “New contributions to the skull anatomy of spinosaurid theropods” was published by Iker Isasmendi (lead author) and Xavier Pereda of the UPV/EHU-University of the Basque Country, Pablo Navarro of the UR-University of La Rioja, Angélica Torices, director of the Chair of Paleontology at the UR, plus other experts of the Complutense University of Madrid and the Palaeontological Visitors’ Center of La Rioja.

The scientists have reassessed fossil jaw remains published by Viera and Torres in 1995 and found in 1983 in a Lower Cretaceous site at Igea (La Rioja, Spain). The remains constitute a fragment of a left maxilla belonging to a carnivorous dinosaur and in which eight alveoli have been preserved. Using microCT techniques, they discovered the remains of several teeth developing simultaneously in one of these dental sockets.

“We recognized up to three generations of teeth in the same alveolus: the functional tooth of the animal, another tooth being formed and which would replace the first, and the germ of the one that would end up replacing the second,” explained Pablo Navarro of the UR.

“This suggests very rapid tooth replacement and is probably one of the reasons why so many spinosaurid teeth can be found on the Iberian Peninsula during the Lower Cretaceous,” added the co-author of the paper.

To date, some species of spinosaurids—medium/large carnivorous dinosaurs with elongated skulls and crocodile-like conical teeth—were known to replace their teeth faster than other theropods, in just two months (replacement rate estimated to be 60–68 days); the research confirms that this is a trait shared by the whole group and provides evidence of how this change occurred, i.e., it was made possible by the development of several replacement teeth at the same time.

“Throughout their lives these animals grew new teeth that gradually replaced the original ones and caused them to fall out. This means that the same animal could generate multiple teeth,” said Pablo Navarro.

“These teeth, more or less conical in shape and a centimeter in size, were transported by rivers, accumulated in lake areas and, over time, became fossilized,” said the researcher. “They are one of the most common vertebrate remains in Iberian sites of the Lower Cretaceous (between 145 and 113 million years ago).”

Although it is not known precisely why their teeth were replaced so often, it is believed that this allowed them to possess a greater number of functional teeth at all times. This was a decisive advantage when withstanding the considerable effort required to hold their prey by trapping them between their jaws.

In addition to these findings, the research has enabled the classification of the jaw studied to be clarified: the experts do not attribute it, as previously thought, to the genus Baryonix, but to another type of spinosaurid very close to it, an indeterminate baryonychid.

The paleontological studies carried out to date at Igea are significant because of the presence of numerous spinosaur skeletal remains, including partial skeletons belonging to several individuals. “The current research will allow our knowledge about the diversity of this unique group of carnivorous dinosaurs to be improved. It is likely that at least two different species are represented at the Igea sites,” said Erik Isasmendi and Xabier Pereda-Suberbiola, paleontologists in the UPV/EHU’s Department of Geology; consequently, this Riojan locality is one of the world’s leading locations in the study of spinosaurs. More information: Erik Isasmendi et al, New contributions to the skull anatomy of spinosaurid theropods: Baryonychinae maxilla from the Early Cretaceous of Igea (La Rioja, Spain), Historical Biology (2022). DOI: 10.1080/08912963.2022.2069019 Provided by University of the Basque Country Citation: Speed of spinosaurid dinosaur teeth replacement accounts for their overabundance in Cretaceous sites (2022, August 9) retrieved 9 August 2022 from https://phys.org/news/2022-08-spinosaurid-dinosaur-teeth-accounts-overabundance.html This document is subject to copyright. Apart from any fair dealing for the purpose of private study or research, no part may be reproduced without the written permission. The content is provided for information purposes only.

TECH NEWS RELATED

Xiamen Tianma Display Technology begins to ship flexible OLED panels

China-based Xiamen Tianma Display Technology (Tianma Display) began to ship flexible OLED panels used in smartphones and wearable devices in August 2022, according to industry sources. Being a joint-venture maker established in January 2020 by China-based panel maker Tianma Microelectronics, Tianma Display in October 2020 began to construct a ...

View more: Xiamen Tianma Display Technology begins to ship flexible OLED panels

Meta Platforms pauses hiring, warns of restructuring

ETtechFacebook-parent Meta Platforms will freeze hiring and further restructure amid an uncertain macroeconomic situation, Bloomberg News reported on Thursday, quoting Chief Executive Mark Zuckerberg’s communication with employees.Several tech companies have been forced to slash headcount in recent months as advertisers trim spending to prepare for a looming recession.“I had hoped ...

View more: Meta Platforms pauses hiring, warns of restructuring

Tech time warp: What was hot in 1983

Ah, the 1980s and ’90s. A time when folk were regularly subjected to seven-hour holiday video marathons. Yes, the advent of the humble camcorder meant dads all over the world immediately imagined themselves to be the next Steven Spielberg, spending half of the time trying to work out if ...

View more: Tech time warp: What was hot in 1983

Eliud Kipchoge broke the men’s marathon record by 30 seconds. How close is the official sub-2 hour barrier now?

Sixty-nine seconds. In that time, you could reheat a cuppa in the microwave or get halfway through brushing your teeth. But for Eliud Kipchoge, the greatest men’s marathoner of all time, his life’s work has come down to a cruel clutch of seconds. After surpassing his own world record in ...

View more: Eliud Kipchoge broke the men’s marathon record by 30 seconds. How close is the official sub-2 hour barrier now?

Anthony Mackie doesn’t know if Captain America will be in Thunderbolts

Plenty of rumors before Marvel’s Comic-Con 2022 event suggested that Kevin Feige might bring the Thunderbolts to the MCU. And Feige delivered in July, revealing that the movie will end Phase 4. But we had to wait for D23 Expo to learn the team’s initial roster. As expected, Bucky ...

View more: Anthony Mackie doesn’t know if Captain America will be in Thunderbolts

Apple TV Plus shares release dates for 4 returning shows

Apple doesn’t release dozens of shows on its streaming service every month, so it’s more of an event when a new season of a series hits Apple TV Plus. That’s why this week is becoming a rather exciting one for subscribers. On Thursday, Apple surprised us with a bunch ...

View more: Apple TV Plus shares release dates for 4 returning shows

Facebook owner Meta to cut headcount for first time amid slow ad revenue growth and dour economic outlook

Meta Platforms Inc chief executive officer Mark Zuckerberg outlined sweeping plans to reorganise teams and reduce headcount for the first time ever, calling an end to an era of rapid growth at the social media giant. In what would be the first major budget cut since the founding of ...

View more: Facebook owner Meta to cut headcount for first time amid slow ad revenue growth and dour economic outlook

Tecno Phantom X2 5G passes by FCC with huge cameras

Infinix may be in the spotlight with the launch of the Infinix Zero 20, and due to its upcoming 180W charging smartphone. However, Tecno is also another relevant company under the Transsion group’s wings. The brand also wants to prove itself to global customers and has been making decent phones ...

View more: Tecno Phantom X2 5G passes by FCC with huge cameras

NASA Astronauts From International Space Station Witnesses Hurricane Ian Heading Towards Florida

Indonesia's Traveloka gets $300M investment from BlackRock, Allianz, Orion Capital Asia and others

Razer Edge 5G – the Nintendo Switch killer is coming

AirPods Pro 2 irony – environmentally unfriendly, impossible to repair

Twitter to Add Video Feed to the Explore Tab and Immersive Media Viewer, Reveals Testing for Edit Feature

Anker's new Soundcore Liberty earbuds has heart-rate tracking, ANC, and spatial audio

Jewel Changi Airport welcomes Singapore's second Dyson Demo Store Service Centre

Get the Best Projector at Home With VANKYO Performance V700W Livehouse Projector

If you love action-packed K-dramas, put this new Netflix series on your watch list

NASA releases first Juno image from Europa flyby

SpaceX’s Starlink Speed Slows Down Due to Satellite Congestion, Astronomers to Put a Stop To It?

Lenovo IdeaPad 5 Gaming Chromebook in the Works, To Deliver Powerful Laptop Powered by Google

OTHER TECH NEWS

Top Car News Car News