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.

New monkeyflower species discovery in Shetland


This 16 August 2017 video is called Scientists discover new plant in Shetland.

From the University of Stirling in Scotland:

New plant discovered in Shetland

August 16, 2017

Scientists at the University of Stirling have discovered a new type of plant growing in Shetland — with its evolution only having occurred in the last 200 years.

The new plant is a descendant of a non-native species, the yellow monkeyflower (Mimulus guttatus), which colonised the United Kingdom in Victorian times. It has evolved through the doubling of the number of chromosomes, known as genome duplication or polyploidy.

The plant, referred to as ‘Shetland’s monkeyflower’, produces yellow flowers with small red spots. It is larger than the typical monkeyflower and its flowers are more open.

Researchers say the finding is significant as it shows that a major evolutionary step can occur in non-native species over a short period of time, rather than over thousands of years.

Associate Professor Dr Mario Vallejo-Marin said: “Evolution is often thought to be a slow process taking thousands or millions of years. Yet we show that a major evolutionary step can occur in a couple hundred years.”

A team from Stirling’s Biological and Environmental Sciences, working with Dr James Higgins at the University of Leicester, carried out tests after a “chance encounter” with the plant while conducting fieldwork near Quarff, Shetland.

Led by postdoctoral researcher Dr Violeta Simon-Porcar, they measured the plant’s genome size and surveyed 30 populations of monkeyflowers from Shetland and across the United Kingdom.

The plants were then grown under controlled conditions and their floral and vegetative characteristics were measured to compare the effect of genome duplication in morphology and flowering time.

The team also conducted genetic analyses to investigate the relationship between the new polyploid plant and other populations in the Shetland Isles.

Genome duplication is common in the evolutionary history of flowering plants and many crops — such as potatoes, tobacco and coffee — are polyploids. However, it is rare to witness the phenomenon in recent history.

While genome duplication seems to be particularly common in hybrids between different species, the new plant has doubled its genome without hybridisation and has the same species as both its father and mother.

The Stirling team say that young polyploids, such as the new plant, provide an opportunity to investigate the early stages of an important evolutionary process.

Dr Vallejo-Marin said: “The fact that the new polyploid involves a non-native plant is poignant, given the fact that human activities are transporting all sorts of animal and plant species well beyond their native habitats. This raises the possibility that non-native species may increasingly participate in major biological processes, including the formation of new types pf plants and animals.”

He continued: “We found that genome duplication has immediate effects on the morphology and life strategy of this plant. Plants with double the DNA in their cells produce larger flowers, larger leaves, thicker stems, but they also take longer to flower.

“Although these type of changes are predicted by theory, demonstrating them is complicated as in older polyploids the parental species may be missing or may have evolved since the separation of the polyploid and non-polyploid lineages.”

Dr Simon-Porcar was funded through a postdoctoral fellowship from Plant Fellows.

The scientific description of this is here.

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.

Prehistoric spider journey from Africa to Australia?


This video from Australia says about itself:

2 August 2017

This spider floated 6,000 miles across the Indian Ocean millions of years ago.

By Sarah Zielinski, 9:00am, August 15, 2017:

These spiders crossed an ocean to get to Australia

If you look at a map of the world, it’s easy to think that the vast oceans would be effective barriers to the movement of land animals. And while an elephant can’t swim across the Pacific, it turns out that plenty of plants and animals — and even people — have unintentionally floated across oceans from one continent to another. Now comes evidence that tiny, sedentary trapdoor spiders made such a journey millions of years ago, taking them from Africa all the way across the Indian Ocean to Australia.

Moggridgea rainbowi spiders from Kangaroo Island, off the south coast of Australia, are known as trapdoor spiders because they build a silk-lined burrow in the ground with a secure-fitting lid, notes Sophie Harrison of the University of Adelaide in Australia. The burrow and trapdoor provides the spiders with shelter and protection as well as a means for capturing prey. And it means that the spiders don’t really need to travel farther than a few meters over the course of a lifetime.

There was evidence, though, that the ancestors of these Australian spiders might have traveled millions of meters to get to Australia — from Africa. That isn’t as odd as it might seem, since Australia used to be connected to other continents long ago in the supercontinent Gondwana. And humans have been known to transport species all over the planet. But there’s a third option, too: The spiders might have floated their way across an ocean.

To figure out which story is most likely true, Harrison and her colleagues looked at the spider’s genes. They turned to six genes that have been well-studied by spider biologists seeking to understand relationships between species. The researchers looked at those genes in seven M. rainbowi specimens from Kangaroo Island, five species of Moggridgea spiders from South Africa and seven species of southwestern Australia spiders from the closely related genus Bertmainius.

Using that data, the researchers built a spider family tree that showed which species were most closely related and how long ago their most recent common ancestor lived. M. rainbowi was most closely related to the African Moggridgea spiders, the analysis revealed. And the species split off some 2 million to 16 million years ago, Harrison and her colleagues report August 2 in PLOS ONE.

The timing of the divergence was long after Gondwana split up. And it was long before either the ancestors of Australia’s aboriginal people or later Europeans showed up on the Australian continent. While it may be improbable that a colony of spiders survived a journey of 10,000 kilometers across the Indian Ocean, that is the most likely explanation for how the trapdoor spiders got to Kangaroo Island, the researchers conclude.

Such an ocean journey would not be unprecedented for spiders in this genus, Harrison and her colleagues note. There are three species of Moggridgea spiders that are known to live on islands off the shore of the African continent. Two live on islands that were once part of the mainland, and they may have diverged at the same time that their islands separated from Africa. But the third, M. nesiota, lives on the Comoros, which are volcanic islands. The spiders must have traveled across 340 kilometers of ocean to get there.

These types of spiders may be well-suited to ocean travel. If a large swatch of land washes into the sea, laden with arachnids, the spiders may be able to hide out in their nests for the journey. Plus, they don’t need a lot of food, can resist drowning and even “hold their breath” and survive on stored oxygen during periods of temporary flooding, the researchers note.

‘Extinct’ Táchira antpitta rediscovered in Venezuela


Táchira antpitta

From the Cornell Lab of Ornithology in the USA today:

“Lost” Antpitta Rediscovered

After a 60-year absence, the secretive Táchira Antpitta has been rediscovered in Venezuela. Until now, four specimens from the 1950s provided scant information about the species. Continued deforestation and human conflict in its home range mean that time is of the essence to save this critically endangered species. Read about the exciting rediscovery.

Did you know that more than 50 seemingly lost birds have been rediscovered since 2000? Read more in our Living Bird feature, “Lost Birds: The Search to Rediscover Species that Might Not be Extinct.”