Oldest giant ichthyosaur discovery


Cymbospondylus

Cymbospondylus

From ScienceDaily, 23 December 2021, by the Natural History Museum of Los Angeles County in the USA:

The two-meter skull of a newly discovered species of giant ichthyosaur, the earliest known, is shedding new light on the marine reptiles’ rapid growth into behemoths of the Dinosaurian oceans, and helping us better understand the journey of modern cetaceans (whales and dolphins) to becoming the largest animals to ever inhabit the Earth.

While dinosaurs ruled the land, ichthyosaurs and other aquatic reptiles (that were emphatically not dinosaurs) ruled the waves, reaching similarly gargantuan sizes and species diversity. Evolving fins and hydrodynamic body-shapes seen in both fish and whales, ichthyosaurs swam the ancient oceans for nearly the entirety of the Age of Dinosaurs.

“Ichthyosaurs derive from an as yet unknown group of land-living reptiles and were air-breathing themselves,” says lead author Dr. Martin Sander, paleontologist at the University of Bonn and Research Associate with the Dinosaur Institute at the Natural History Museum of Los Angeles County (NHM). “From the first skeleton discoveries in southern England and Germany over 250 years ago, these ‘fish-saurians’ were among the first large fossil reptiles known to science, long before the dinosaurs, and they have captured the popular imagination ever since.”

Excavated from a rock unit called the Fossil Hill Member in the Augusta Mountains of Nevada, the well-preserved skull, along with part of the backbone, shoulder, and forefin, date back to the Middle Triassic (247.2-237 million years ago), representing the earliest case of an ichthyosaur reaching epic proportions. As big as a large sperm whale at more than 17 meters (55.78 feet) long, the newly named Cymbospondylus youngorum is the largest animal yet discovered from that time period, on land or in the sea. In fact, it was the first giant creature to ever inhabit the Earth that we know of.

“The importance of the find was not immediately apparent,” notes Dr. Sander, “because only a few vertebrae were exposed on the side of the canyon. However, the anatomy of the vertebrae suggested that the front end of the animal might still be hidden in the rocks. Then, one cold September day in 2011, the crew needed a warm-up and tested this suggestion by excavation, finding the skull, forelimbs, and chest region.”

The new name for the species, C. youngorum, honors a happy coincidence, the sponsoring of the fieldwork by Great Basin Brewery of Reno, owned and operated by Tom and Bonda Young, the inventors of the locally famous Icky beer which features an ichthyosaur on its label.

In other mountain ranges of Nevada, paleontologists have been recovering fossils from the Fossil Hill Member’s limestone, shale, and siltstone since 1902, opening a window into the Triassic. The mountains connect our present to ancient oceans and have produced many species of ammonites, shelled ancestors of modern cephalopods like cuttlefish and octopuses, as well as marine reptiles. All these animal specimens are collectively known as the Fossil Hill Fauna, representing many of C. youngorum’s prey and competitors.

C. youngorum stalked the oceans some 246 million years ago, or only about three million years after the first ichthyosaurs got their fins wet, an amazingly short time to get this big. The elongated snout and conical teeth suggest that C. youngorum preyed on squid and fish, but its size meant that it could have hunted smaller and juvenile marine reptiles as well.

The giant predator probably had some hefty competition. Through sophisticated computational modeling, the authors examined the likely energy running through the Fossil Hill Fauna’s food web, recreating the ancient environment through data, finding that marine food webs were able to support a few more colossal meat-eating ichthyosaurs. Ichthyosaurs of different sizes and survival strategies proliferated, comparable to modern cetaceans’ — from relatively small dolphins to massive filter-feeding baleen whales, and giant squid-hunting sperm whales.

Co-author and ecological modeler Dr. Eva Maria Griebeler from the University of Mainz in Germany notes, “due to their large size and resulting energy demands, the densities of the largest ichthyosaurs from the Fossil Hill Fauna including C. youngourum must have been substantially lower than suggested by our field census. The ecological functioning of this food web from ecological modeling was very exciting as modern highly productive primary producers were absent in Mesozoic food webs and were an important driver in the size evolution of whales.”

Whales and ichthyosaurs share more than a size range. They have similar body plans, and both initially arose after mass extinctions. These similarities make them scientifically valuable for comparative study. The authors combined computer modeling and traditional paleontology to study how these marine animals reached record-setting sizes independently.

“One rather unique aspect of this project is the integrative nature of our approach. We first had to describe the anatomy of the giant skull in detail and determine how this animal is related to other ichthyosaurs,” says senior author Dr. Lars Schmitz, Associate Professor of Biology at Scripps College and Dinosaur Institute Research Associate. “We did not stop there, as we wanted to understand the significance of the new discovery in the context of the large-scale evolutionary pattern of ichthyosaur and whale body sizes, and how the fossil ecosystem of the Fossil Hill Fauna may have functioned. Both the evolutionary and ecological analyses required a substantial amount of computation, ultimately leading to a confluence of modeling with traditional paleontology.”

They found that while both cetaceans and ichthyosaurs evolved very large body sizes, their respective evolutionary trajectories toward gigantism were different. Ichthyosaurs had an initial boom in size, becoming giants early on in their evolutionary history, while whales took much longer to reach the outer limits of huge. They found a connection between large size and raptorial hunting — think of a sperm whale diving down to hunt giant squid — and a connection between large size and a loss of teeth — think of the giant filter-feeding whales that are the largest animals ever to live on Earth.

Ichthyosaurs’ initial foray into gigantism was likely thanks to the boom in ammonites and jawless eel-like conodonts filling the ecological void following the end-Permian mass extinction. While their evolutionary routes were different, both whales and ichthyosaurs relied on exploiting niches in the food chain to make it really big.

“As researchers, we often talk about similarities between ichthyosaurs and cetaceans, but rarely dive into the details. That’s one way this study stands out, as it allowed us to explore and gain some additional insight into body size evolution within these groups of marine tetrapods,” says NHM’s Associate Curator of Mammalogy (Marine Mammals), Dr. Jorge Velez-Juarbe. “Another interesting aspect is that Cymbospondylus youngorum and the rest of the Fossil Hill Fauna are a testament to the resilience of life in the oceans after the worst mass extinction in Earth’s history. You can say this is the first big splash for tetrapods in the oceans.”

C. youngorum will be permanently housed at the Natural History Museum of Los Angeles County, where it is currently on view.

Making a red-tailed hawk carving


This video from the USA says about itself:

Enjoy this archived live conversation with artist and Red-tailed Hawk cam aficionado David Cohen as he explains the inspiration and craftsmanship behind his carving of the Cornell Hawks nest that is now on display at Cornell University’s Corson-Mudd Hall.

Good whimbrel news from the USA


This 16 June 2021 video says about itself:

Discovery at Deveaux! This short film follows a team of shorebird biologists as they confirm the first census of a newly discovered Whimbrel roost in 2019. The final counts amount to nearly 20,000 individuals, representing half of the entire Atlantic Flyway population of this declining species using a single barrier island in South Carolina.

Vast flocks of Whimbrels were thought to be a thing of the past, something out of tattered ornithological journals from a century ago. Then a South Carolina wildlife biologist made a major discovery: Nearly 20,000 birds roosting nightly on a sandbar just off the coast—the largest known concentration of this rapidly declining shorebird anywhere on Earth. Read the story.

Wildness on a Whim: South Carolina poet and ornithologist Dr. J. Drew Lanham reflects on the Deveaux Bank Whimbrel roost as sign of a new kind of hope—and a new definition of wildness. Read his essay.

Studying curlew in England


This 1 October 2021 video from England says about itself:

Harry Ewing, PhD student at the University of East Anglia and BTO, shares his research into Curlew in Breckland, tells us how the COVID-19 pandemic affected his work and thanks BTO major donors for supporting an extra field season to gather more data on this declining species.

Bittern, buzzard, bearded reedlings


Bittern area, September 2021

This photo shows the view from a hide in the Rottige Meente nature reserve in Friesland province in the Netherlands. In September, we saw a bittern there. All three photos in this blog post are cellphone photos.

A few days later, a buzzard, hundreds of lapwings and a marsh harrier from that hide.

Nearly all days, bearded reedlings. And dragonflies.

Rottige Meente, September 2021

And gadwall ducks. Sometimes also mallards and shovelers.

Rottige Meente water, September 2021

Brown thrasher in Georgia, USA


This video from the USA says about itself:

Brown Thrasher Poses For Cam In Savannah, Georgia – Aug. 27, 2021

Brown Thrashers are secretive, and hard to spot in their favorite spots under dense vegetation, but they can make a lot of noise as they rummage through the leaf litter. Here, the Savannah Osprey cam zooms in on a perching thrasher before it has a chance to depart from a branch.

310-million-year-old horseshoe crab brain discovery


The brain (white at center) of an extinct horseshoe crab called Euproops danae was fossilized in a clay mineral called kaolinite. The whole crab stretches only about 10 millimeters. R. Bicknell

By Rebecca Dzombak:

August 20, 2021 at 8:00 am

How fossilization preserved a 310-million-year-old horseshoe crab’s brain

A newly analyzed specimen is a ‘one-in-a-million’ find, researchers say

Paleontologists can spend years carefully splitting rocks in search of the perfect fossil. But with a 310-million-year-old horseshoe crab brain, nature did the work, breaking the fossil in just the right way to reveal the ancient arthropod’s central nervous system.

Of all soft tissues, brains are notoriously difficult to preserve in any form (SN: 10/31/16). Stumbling across such a detailed specimen purely by chance was “a one-in-a-million find, if not rarer,” says evolutionary paleontologist Russell Bicknell of the University of New England in Armidale, Australia.

The fossilized brain is remarkably similar to the brains of modern horseshoe crabs, giving clues to the arthropods’ evolution, Bicknell and colleagues report July 26 in Geology. And the brain’s peculiar mode of preservation could point paleontologists toward new places to look for hard-to-find fossils of soft tissues.