Bite Marks Indicate the Terrobird Was Likely Preyed Upon by an Even Larger Creature 13 Million Years Ago

Sporting a shaft-like beak capable of inflicting devastating blows, the infamous terrorist birds have emerged as formidable adversaries for many species.

Around 13 million years ago, however, one such bird may have fallen prey to even larger predators. A group of Colombian paleontologists made this discovery while analyzing bite marks found on fossilized remnants of the fearsome avian.

Their findings were published in the peer-reviewed journal “Biology Letters.” The researchers hypothesized that the bird was killed and consumed by medium-sized caimans, a crocodilian species.

Andres Link, the study’s lead investigator, shared with NBC News via email, “This represents a captivating tale of interaction between two iconic animals from the past. Not only did we identify the first instance of terrorist birds in northern South America, but we also found the tooth marks of the large caiman that likely preyed on it.”

Most unusual fossils of terrorist birds have previously been found in the southern regions of the continent, as noted in this report.

Link, an associate professor in biological sciences at the University of Los Andes, remarked that while tooth marks are “not uncommon” in the fossil record, it is “thrilling” to find proof that apex predators could fall victim to others.

The paper in “Biology Letters” highlights that there were no signs of healing on the tooth marks, indicating a fatal attack.

This leads researchers to conclude that terrorist birds may have been more vulnerable to predation than previously believed.

Julian Bayona Becerra / Biology Letters

To determine the identity of the predator, Link and his team performed scans of the fossils and examined the size, shape, and arrangement of the tooth marks. By comparing these features with alligator-like teeth from the region, they deduced that the marks likely belong to a caiman measuring about 15 feet long.

Link noted that it was challenging to ascertain whether the caiman consumed the terrorist bird after killing it or scavenged the carcass. If the bird was alive during the encounter, it likely happened while it was drinking at the riverbank; alternatively, if it was already deceased, the caiman may have found it near the water.

“This narrative remains incomplete, as we lack further evidence to support either hypothesis,” Link stated.

The discovery calls into question the traditional view of “linear relationships between predators and their herbivore prey,” he remarked, adding, “The food web is considerably more intricate.”

The lower section of the bird’s left leg featured in this research was excavated two decades ago by local paleontologist Cesar Perdomo in the renowned La Venta fossil layer of Colombia.

Source: www.nbcnews.com

Evidence shows pregnant sharks are preyed on by larger sharks

Prior to giving birth, the pregnant porbeagle shark was expected to give birth soon, when one of the two tracking tags attached to the shark by marine scientists resurfaced near Bermuda.

Surprisingly, the tag emerged much earlier than anticipated. It had been affixed to the 7-foot-long shark only 158 days prior, after conducting an ultrasound scan off the coast of Cape Cod, Massachusetts, in October 2020. The tag was supposed to remain attached for about a year.

“Something seemed amiss,” stated Brooke Anderson, a shark researcher at Arizona State University during that time.

The second tag, which was designed to transmit a signal when the shark’s fin breached the surface, never sent a signal again.

Data collected from the retrieved “pop-off” tag revealed an unusual pattern: for the initial five months, the depth and temperature information appeared normal for this species, but then deviations started to occur.

“Unexpectedly, temperatures suddenly spiked and remained high even at depths of 600 meters,” recounted Anderson.

The diving patterns of the creatures also became peculiar.

Of the 11 porbeagle sharks that researchers tagged, eight were pregnant, including this one.
John Dodd

“All the data pointed in one direction: she had been consumed,” remarked Anderson.

The researchers ascertained that the irregular readings from the tag were due to it having been inside another animal’s stomach for several days.

Their conclusions were detailed in a study published in the Frontiers in Marine Science journal, shedding light on the fact that porbeagle sharks are being preyed upon by much bigger animals.

Naming a few possible predators, the researchers narrowed down their suspects based on biological characteristics – the data didn’t align with a mammal like a killer whale, leading them to focus on warm-blooded sharks with some heat-generating capacity.

“The predator needed to elevate its body temperature above the ambient water, have the size to inflict damage on the porbeagle, and reside in the area of the predation,” explained Anderson.

The researchers inferred that a great white shark or mako shark likely devoured the pregnant porbeagle, temporarily swallowing the tag.

“Our estimation is that it was a mature female great white shark, possibly exceeding 15 feet in length,” disclosed Anderson.

Previously, the notion that porbeagle sharks might fall prey to larger creatures had not been considered, she added.

Originally, their team aimed to track pregnant porbeagle sharks during their gestation period and pinpoint where they typically give birth.

Across two Atlantic seasons, they located and tagged a total of 11 porbeagle sharks, hauling each one onto the boat, treating them with aerated seawater, and concealing their eyes with wet towels.

“We operated like a NASCAR pit crew,” described Anderson. Eight of these sharks were pregnant.

Their expectations didn’t encompass uncovering a profound deep-sea mystery.

Matt Davis, a marine resources scientist from the Maine Department of Marine Resources not involved in the research, acknowledged that the study’s conclusions were plausible.

This incident underscores the continued need for scientific exploration of mid-depth ocean life and predator-prey interactions, added Davis.

The porbeagle shark is categorized as an endangered species by the International Union for Conservation of Nature. Overfishing activities began in the 1960s, causing a population decline of 75 to 80 percent by 2001, as per Anderson.

While the species is recuperating due to fishing regulations, their longer lifespan and lower reproductive rate mean a protracted recovery process.

“We must continue tagging and monitoring these sharks to understand the frequency of such incidents,” emphasized Anderson regarding the predation. “In an instant, this critically endangered species lost not just its essential breeding females, but all its developing offspring as well. It is crucial to grasp both the frequency and impact of such events.”

Their research could play a pivotal role in restoring a healthy shark population in the Atlantic, where sharks prey on sharks.

Source: www.nbcnews.com

Paleontologists say that crocodiles and tiger sharks preyed on Miocene dugongs

Paleontologists have unearthed the 20-million-year-old fossil skeleton of a species of sirenian mammal from the dugong family. Cleavage Shark and crocodile bite marks have been found in northwestern Venezuela. The most prominent bite marks are from deep, dragging tooth impacts concentrated on the snout of the animals. Researchers interpret this as the result of active predation, as they are similar to bite marks made by crocodiles when they grab and roll their prey. Moreover, shark bite marks can be observed throughout Venezuela. CleavageThe skeleton of Tiger shark (Galeocerdo Aduncus) The teeth associated with this skeleton.

Tiger sharks are congregating to make easy catches of larger prey as crocodiles attack ancient dugong-like siren mammals. CleavageImage courtesy of Jaime Bran Sarmiento.

“Our discovery adds to the growing evidence that food chains millions of years ago worked in a similar way to how they do today,” said Dr Aldo Benitez Palomino, a paleontologist at the institute. University of Zurich.

“Today, when we observe predators in the wild, we often find dead prey, indicating that the animal also served as a food source for other animals. However, the fossil record of this is rare.”

“It was unclear which animals would serve this purpose as a food source for multiple predators.”

“Our previous research has confirmed that several shark species scavenge sperm whale carcasses, and this new study highlights the importance of sea cows in the food chain.”

Evidence for food web interactions is abundant in the fossil record, but most of it is represented by fragmentary fossils that provide ambiguous meaning.

Therefore, it is often difficult to distinguish between active feeding and signs of saprophytic activity.

“Our results are one of the few to document multiple predators on a single prey and provide a glimpse into food webs in the region during the Miocene,” Dr Benitez-Palomino said.

The dugong specimen studied by the team was collected from an outcrop of the Agua Clara Formation, south of the city of Coro, Venezuela.

The fossil is closely related to a species of sirenian in the dugong family. Cleavage.

“We first heard about the site through word of mouth from local farmers who noticed some unusual 'rocks'. We were intrigued and decided to investigate,” said Professor Marcelo Sánchez-Vilagra from the University of Zurich.

“Initially, we weren't familiar with the geology of the site, and the first fossil we unearthed was just part of a skull.”

“It took us a while to identify what it was – very strange looking remains of a sea cow.”

“By studying geological maps and examining the sediments at the new site, we were able to determine the age of the rocks in which the fossils were found.”

“One of the factors that allowed us to observe evidence of aquatic mammal predation, which is known to exist in this region, is the extremely well-preserved cortical layer of the fossil, which is likely due to the fine sediment in which the fossil was embedded.”

“After locating the fossils, our team organized a paleontological rescue operation, employing extraction techniques with full case protection.”

“A team of five people was involved in working on the fossil, and the job took about seven hours.”

“The subsequent preparations, particularly the meticulous task of preparing and repairing the skull, took several months.”

Team Survey results Published in Journal of Vertebrate Paleontology.

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Aldo Benitez Palomino othersTrophic interactions between sharks and crocodiles and Sirenia in the Miocene of Venezuela. Journal of Vertebrate Paleontologyy, published online August 28, 2024, doi: 10.1080/02724634.2024.2381505

Source: www.sci.news