Fossil and living porcupinefish, new research


This video says about itself:

Porcupine fish rescue

21 March 2016

Our guys came across an entangled porcupine fish while snorkeling. The little guy was freed using a broken bottle. Clever.

From the Smithsonian Tropical Research Institute in Panama:

Comparing the jaws of porcupine fish reveals three new species

August 16, 2017

Researchers at the Smithsonian Tropical Research Institute and colleagues compared fossil porcupine fish jaws and tooth plates collected on expeditions to Panama, Colombia, Venezuela and Brazil with those from museum specimens and modern porcupine fish, revealing three new species.

Startled porcupine fish suck in air or water to inflate their bodies, becoming a prickly balloon-like shape to defend themselves from predators and some contain a neurotoxin a thousand times more potent than cyanide in their ovaries and livers. They are also good at offense, crushing the shells of clams and other marine mollusks with beak-like jaws so tough that they are preserved as fossils to be discovered millions of years later.

Two of the newly discovered species, named Chilomycterus tyleri, in honor of the Smithsonian’s James C. Tyler, senior scientist emeritus at the National Museum of Natural History — an expert on this group of fish — and C. expectatus, named for the arrangement of its dental plates, were discovered in Panama’s Gatun formation.

The third new species, Diodon serratus, named for the serrated edge of its crushing dental sheet, comes from the Socorro Formation in Venezuela. When Darwin traveled to the tropics on the Voyage of the Beagle, he noticed this fish that swims upside down when inflated. He even mentioned a report from a fellow naturalist, that porcupine fish could gnaw their way out of the stomach of a shark.

Today 18 species of porcupine fish populate tropical seas worldwide. Species in the genus Diodon are common in shallow, tropical waters of both the Atlantic and Pacific. In contrast, only one species of the genus Chilomycterus is found in the Eastern Pacific. The rest are in the Atlantic.

When the Isthmus of Panama arose from the sea to connect North and South America and divide the Atlantic from the Pacific, the oceans on each side of this intercontinental bridge changed forever. The Eastern Pacific became cooler and more nutrient rich and the Caribbean because warmer and more nutrient poor, characterized by more coral reefs and seagrass beds.

This research team hopes to better understand why there was only one Chilomycterus species in a fossil deposit near Panama’s Tuira river on the Pacific side of the isthmus of Panama.

Dinosaur age damselfly named after David Attenborough


This video says about itself:

15 August 2017

Damselfly thought to be 100 MILLION years old named after Sir David Attenborough

TV naturalist Sir David Attenborough was last night said to be delighted after a prehistoric insect was named in his honour. Prof. Jarzembowski said: “Dragonflies in amber are extremely rare and the recent discoveries by my Chinese colleagues are a new window on the past. “It is tradition in taxonomy – the naming of a new species – to contact the person concerned. “Sir David was delighted because he is not only interested in the story of amber, but also a president of the British Dragonfly Society.”

Lead author Daran Zheng from the Nanjing Institute of Geology and Palaeontology, Chinese Academy of Sciences, commented: “Mesosticta davidattenboroughi is quite unique because we have uncovered a new species.” The naming of the species was revealed in the Journal of Systematic Palaeontology.

Mesosticta davidattenboroughi is just the latest species to be named after Sir David whose wildlife documentaries have enchanted the world. Others include a carnivorous plant, a butterfly, a tiny spider, a Peruvian frog and a Namibian lizard. Among the prehistoric species named after him are a Mesozoic reptile, a fossilised armoured fish and a 430 million-year-old crustacean.

From ScienceDaily:

David Attenborough gains new species namesake

August 16, 2017

A new species of damselfly from the Cretaceous period has been named after the iconic naturalist and TV presenter Sir David Attenborough.

The new discovery, described in detail in the Journal of Systematic Palaeontology, was made in the Hukawng Valley of Kachin Province in Myanmar. The fossil was found in a piece of mid-Cretaceous Burmese amber. The full scientific name for the new species, belonging to a group more commonly known as shadowdamsels, is Mesosticta davidattenboroughi. Researchers decided to name the new species after David Attenborough because of his long-standing appreciation of dragonflies, and to celebrate his recent 90th birthday.

The fossil itself is extremely well preserved as it is encased in yellow transparent amber and includes a complete set of wings. With the aid of photo technology, researchers were able to digitally enhance and build a clear three-dimensional picture of the new species, showing that it differed from previously described fossils, notably in the shorter wing length.

Lead author Daran Zheng from the Nanjing Institute of Geology and Palaeontology, Chinese Academy of Sciences, commented, “Mesosticta davidattenboroughi is quite unique because we have uncovered a new species and it confirms the previous attribution of Mesosticta to the Platystictidae. It is the first fossil group of modern platystictid damselflies and documents the appearance of Platystictidae as early as mid-Cretaceous.”

The discovery of insect remains in amber is not uncommon, however this particular family of damselflies are much less frequently found and their fossil record is poor compared to many other families making the discovery especially unusual.

Mesosticta davidattenboroughi joins a long list of animals which have been named after Sir David Attenborough, including a weevil and fossil species of a plesiosaur and a fish.

This research was supported by the National Natural Science Foundation of China, Youth Innovation Promotion Association of the Chinese Academy of Sciences and the HKU Seed Funding Program for Basic Research.

See also here. And here.

Dinosaur age flowering trees discovered


Tropidogyne pentaptera. 100-million-year-old fossilized flower identified and named by OSU researchers George Poinar Jr. and Kenton Chambers. Credit: Image courtesy of George Poinar Jr., Oregon State University

From Oregon State University in the USA:

Seven complete specimens of new flower, all 100 million years old

August 15, 2017

A Triceratops or Tyrannosaurus rex bulling its way through a pine forest likely dislodged flowers that 100 million years later have been identified in their fossilized form as a new species of tree.

George Poinar Jr., professor emeritus in Oregon State University’s College of Science, said it’s the first time seven complete flowers of this age have been reported in a single study. The flowers range from 3.4 to 5 millimeters in diameter, necessitating study under a microscope.

Poinar and collaborator Kenton Chambers, professor emeritus in OSU’s College of Agricultural Sciences, named the discovery Tropidogyne pentaptera based on the flowers’ five firm, spreading sepals; the Greek word for five is “penta,” and “pteron” means wing.

“The amber preserved the floral parts so well that they look like they were just picked from the garden,” Poinar said. “Dinosaurs may have knocked the branches that dropped the flowers into resin deposits on the bark of an araucaria tree, which is thought to have produced the resin that fossilized into the amber. Araucaria trees are related to kauri pines found today in New Zealand and Australia, and kauri pines produce a special resin that resists weathering.”

This study builds on earlier research also involving Burmese amber in which Poinar and Chambers described another species in the same angiosperm genus, Tropidogyne pikei; that species was named for its flower’s discoverer, Ted Pike. Findings were recently published in Paleodiversity.

“The new species has spreading, veiny sepals, a nectar disc, and a ribbed inferior ovary like T. pikei,” Poinar said. “But it’s different in that it’s bicarpellate, with two elongated and slender styles, and the ribs of its inferior ovary don’t have darkly pigmented terminal glands like T. pikei.”

Both species have been placed in the extant family Cunoniaceae, a widespread Southern Hemisphere family of 27 genera.

Poinar said T. pentaptera was probably a rainforest tree.

“In their general shape and venation pattern, the fossil flowers closely resemble those of the genus Ceratopetalum that occur in Australia and Papua-New Guinea,” he said. “One extant species is C. gummiferum, which is known as the New South Wales Christmas bush because its five sepals turn bright reddish pink close to Christmas.”

Another extant species in Australia is the coach wood tree, C. apetalum, which like the new species has no petals, only sepals. The towering coach wood tree grows to heights of greater than 120 feet, can live for centuries and produces lumber for flooring, furniture and cabinetwork.

So what explains the relationship between a mid-Cretaceous Tropidogyne from Myanmar, formerly known as Burma, and an extant Ceratopetalum from Australia, more than 4,000 miles and an ocean away to the southeast?

That’s easy, Poinar said, if you consider the geological history of the regions.

“Probably the amber site in Myanmar was part of Greater India that separated from the southern hemisphere, the supercontinent Gondwanaland, and drifted to southern Asia,” he said. “Malaysia, including Burma, was formed during the Paleozoic and Mesozoic eras by subduction of terranes that successfully separated and then moved northward by continental drift.”

Dinosaur discovery in Chile, missing link?


This video says about itself:

4 September 2015

“Chilesaurus” is an extinct genus of herbivorous theropod dinosaur. The genus is monotypic, represented by the type species “Chilesaurus diegosuarezi“. “Chilesaurus” lived approximately 145 million years ago in the Late Jurassic period of Chile.

Fossils of “Chilesaurus”, a vertebra and a rib, were first discovered on 4 February 2004 by the seven-year-old Diego Suárez who, together with his parents, geologists Manuel Suárez and Rita de la Cruz, was searching for decorative stones in the Aysén Region. More specimens were present that in 2008 were reported as representing several dinosaurian species. Only later was it realised that these belonged to a single species with a bizarre combination of traits.

In 2015, the type species “Chilesaurus diegosuarezi” was named and described by Fernando Emilio Novas, Leonardo Salgado, Manuel Suárez, Federico Lisandro Agnolín, Martín Dário Ezcurra, Nicolás Chimento, Rita de la Cruz, Marcelo Pablo Isasi, Alexander Omar Vargas and David Rubilar-Rogers. The generic name refers to Chile. The specific name honours Diego Suárez.

The holotype, “SNGM-1935”, was found in a layer of the Toqui Formation dating from the late Tithonian. It consists of an articulated rather complete skeleton with skull of a juvenile individual, lacking the feet and most of the tail. Four other partial skeletons and several single bones are the paratypes. They represent juvenile and adult individuals.

“Chilesaurus” measures 3.2 m from nose to tail. The holotype is a smaller individual of half that length.

That was in 2015. But now …

From Biology Letters:

A dinosaur missing-link? Chilesaurus and the early evolution of ornithischian dinosaurs

Matthew G. Baron, Paul M. Barrett

16 August 2017

Abstract

The enigmatic dinosaur taxon Chilesaurus diegosuarezi was originally described as a tetanuran theropod, but this species possesses a highly unusual combination of features that could provide evidence of alternative phylogenetic positions within the clade.

In order to test the relationships of Chilesaurus, we added it to a new dataset of early dinosaurs and other dinosauromorphs. Our analyses recover Chilesaurus in a novel position, as the earliest diverging member of Ornithischia, rather than a tetanuran theropod. The basal position of Chilesaurus within the clade and its suite of anatomical characters suggest that it might represent a ‘transitional’ taxon, bridging the morphological gap between Theropoda and Ornithischia, thereby offering potential insights into the earliest stages of ornithischian evolution, which were previously obscure. For example, our results suggest that pubic retroversion occurred prior to some of the craniodental and postcranial modifications that previously diagnosed the clade (e.g. the presence of a predentary bone and ossified tendons).

1. Introduction

Chilesaurus diegosuarezi is from the Late Jurassic (Tithonian; ca 150 Ma) Toqui Formation of Chile and possesses a bizarre suite of anatomical features that, if considered individually, are usually thought to characterize distantly related dinosaur clades.

Brittle stars fossils discovery in Australia


This video says about itself:

13 August 2017

Australia was a different place 275 million years ago – wild storms surged through icy seas, and marine animals lived a tenuous existence. But brittle stars had a survival strategy.

From the University of Cambridge in England:

Meadow of dancing brittle stars shows evolution at work

August 14, 2017

Newly-described fossil shows how brittle stars evolved in response to pressure from predators, and how an ‘evolutionary hangover’ managed to escape them.

Researchers have described a new species of brittle star, which are closely related to starfish, and showed how these sea creatures evolved in response to the rise of shell-crushing predators during the late Palaeozoic Era. The results, reported in the Journal of Systematic Palaeontology, also suggest that brittle stars evolved new traits before the largest mass extinction event in Earth’s history, and not after, as was the case with many other forms of life.

A fossilised ‘meadow’ of dancing brittle stars — frozen in time in the very spot that they lived — was found in Western Australia and dates from 275 million years ago. It contains several remarkably preserved ‘archaic’ brittle stars, a newly-described genus and species called Teleosaster creasyi. They are the last known complete brittle stars of their kind, an evolutionary hangover pushed to the margins of the world’s oceans by the threat from predators.

The researchers, from the University of Cambridge, suggest that while other species of brittle stars evolved in response to predators such as early forms of rays and crabs, these archaic forms simply moved to where the predators weren’t — namely the seas around Australia, which during the Palaeozoic era was pushed up against Antarctica. In these cold, predator-free waters, the archaic forms were able to grow much larger, and lived at the same time as the modern forms of brittle star, which still exist today.

Brittle stars consist of a central disc and five whip-like appendages, which are used for locomotion. They first appear in the fossil record about 500 million years ago, in the Ordovician Period, and today there are about 2,100 different species, mostly found in the deep ocean.

Early brittle stars were just that: brittle. During the Palaeozoic Era, when early shell-crushing predators first appeared, brittle stars made for easy prey. At this point, a split in the evolutionary tree appears to have occurred: the archaic, clunky brittle stars moved south to polar waters, while the modern form first began to emerge in response to the threat from predators, and was able to continue to live in the warmer waters closer to the equator. Both forms existed at the same time, but in different parts of the ocean.

“The threat from predation is an under-appreciated driver of evolutionary change,” said study co-author Dr Kenneth McNamara of Cambridge’s Department of Earth Sciences. “As more predators began to appear, the brittle stars started to evolve more flexible bodies, which enabled them to either burrow into the sediment, or to move more rapidly to escape.”

About 250 million years ago, the greatest mass extinction in Earth’s history — the Permian-Triassic extinction event, or the “Great Dying” — occurred. More than 90% of marine species and 70% of terrestrial species went extinct, and as a result, most surviving species underwent major evolutionary changes as a result.

“Brittle stars appear to have bucked this trend, however,” said co-author Dr Aaron Hunter, a visiting postdoctoral researcher in the Department of Earth Sciences. “They seem to have evolved before the Great Dying, into a form which we still see today.”

Meadows of brittle stars and other invertebrates such as sea urchins and starfish can still be seen today in the seas around Antarctica. As was the case during the Palaeozoic, the threat from predators is fairly low, although the warming of the Antarctic seas due to climate change has been linked to the recent arrival of armies of king crabs, which represent a real threat to these star-filled meadows.

Ancient Triassic reptile was not aquatic


LAND LIVING Eusaurosphargis dalsassoi, an ancient lizardlike critter (illustrated), wouldn’t swim well, scientists now say, arguing the creature’s style of motion and protective coverings were more suited to land. T. Scheyer/Palaeontological Institute and Museum/University of Zurich, Switzerland

By Ashley Yeager, 7:00am, August 9, 2017:

Fossil find suggests this ancient reptile lurked on land, not in the water

Exquisitely preserved specimen may overturn ideas about spiny creature’s home

A round belly, stubby feet and a tapering tail made one armored reptile a lousy swimmer. Despite earlier reports, Eusaurosphargis dalsassoi might not have swum at all, scientists now say.

E. dalsassoi was first identified in 2003. Fossils were found near Monte San Giorgio at the Swiss-Italian border alongside the remains of marine reptiles and fish that lived roughly 240 million years ago. That association led scientists to conclude the creature was aquatic. But a complete skeleton of E. dalsassoi unearthed in 2002 in the Swiss Alps and recently assembled contradicts that idea.

At just under 20 centimeters long, the fossil, probably of a youngster, shows that E. dalsassoi widened at the stomach and slithered forward with stiff elbow and knee joints and spadelike claws. That’s not a swimmer’s build, paleontologist Torsten Scheyer of the University of Zurich and colleagues report June 30 in Scientific Reports.

Armed with rows of small spikes along its back and spear-shaped plates framing its head, sides and tail, the animal resembled today’s girdled lizards. The researchers speculate that this particular E. dalsassoi died on a beach and then got washed into the ocean.

Biggest dinosaur ever discovered


This video from the American Museum of Natural History in the USA says about itself:

14 January 2016

Measuring 122 feet, the Museum’s new exhibit, The Titanosaur, is big–so big that its head extends outside of the Museum’s fourth-floor gallery where it is now on permanent display.

This species of dinosaur, a giant herbivore that belongs to a group known as titanosaurs, is so new that it has not yet been formally named by the paleontologists who discovered it. The Titanosaur lived in the forests of today’s Patagonia about 100 to 95 million years ago, during the Late Cretaceous period, and weighed 70 tons. It is one of the largest dinosaurs ever discovered.

The fossils on which this cast is based were excavated in the Patagonian desert region of Argentina by a team from the Museo Paleontologico Egidio Feruglio led by José Luis Carballido and Diego Pol, who received his Ph.D. at the American Museum of Natural History.

In this video, Dr. Mark Norell, chair and Macaulay Curator in the Division of Paleontology, describes how such a massive animal could have supported its own weight and why the Titanosaur is one of the more spectacular finds during what he describes as “the golden age of paleontology.”

Learn more about the Titanosaur here.

Then, this dinosaur had no official name yet. Now, it has: Patagotitan mayorum.

It was about 40 meter long, making it the biggest land animal ever.

The discovery was by scientists of the Museo Paleontológico Egidio Feruglio (MEF) in Argentina.

From Proceedings of the Royal Society B:

A new giant titanosaur sheds light on body mass evolution among sauropod dinosaurs

José L. Carballido, Diego Pol, Alejandro Otero, Ignacio A. Cerda, Leonardo Salgado, Alberto C. Garrido, Jahandar Ramezani, Néstor R. Cúneo, Javier M. Krause

Published 9 August 2017

Abstract

Titanosauria was the most diverse and successful lineage of sauropod dinosaurs. This clade had its major radiation during the middle Early Cretaceous and survived up to the end of that period. Among sauropods, this lineage has the most disparate values of body mass, including the smallest and largest sauropods known.

Although recent findings have improved our knowledge on giant titanosaur anatomy, there are still many unknown aspects about their evolution, especially for the most gigantic forms and the evolution of body mass in this clade.

Here we describe a new giant titanosaur, which represents the largest species described so far and one of the most complete titanosaurs. Its inclusion in an extended phylogenetic analysis and the optimization of body mass reveals the presence of an endemic clade of giant titanosaurs inhabited Patagonia between the Albian and the Santonian. This clade includes most of the giant species of titanosaurs and represents the major increase in body mass in the history of Titanosauria.