Dinosaur age sea turtle discovery in Alabama, USA


This is a reconstruction of the new species (Peritresius martini). Credit: Drew Gentry CC-BY

From PLOS:

New ancestor of modern sea turtles found in Alabama

April 18, 2018

A sea turtle discovered in Alabama is a new species from the Late Cretaceous epoch, according to a study published April 18, 2018 in the open-access journal PLOS ONE by Drew Gentry from the University of Alabama at Birmingham, Alabama, USA, and colleagues.

Modern day sea turtles were previously thought to have had a single ancestor of the Peritresius clade during the Late Cretaceous epoch, from about 100 to 66 million years ago. This ancestral species, Peritresius ornatus, lived exclusively in North America, but few Peritresius fossils from this epoch had been found in what is now the southeastern U.S., an area known for producing large numbers of Late Cretaceous marine turtle fossils. In this study, the research team analyzed sea turtle fossils collected from marine sediments in Alabama and Mississippi, dating from about 83 to 66 million years ago.

The researchers identified some of the Alabama fossils as representing a new Peritresius species, which they named Peritresius martini after Mr. George Martin who discovered the fossils. Their identification was based on anatomical features including the shape of the turtle’s shell. Comparing P. martini and P. ornatus, the researchers noted that the shell of P. ornatus is unusual amongst Cretaceous sea turtles in having sculptured skin elements which are well-supplied with blood vessels. This unique feature may suggest that P. ornatus was capable of thermoregulation, which could have enabled Peritresius to keep warm and survive during the cooling period of the Cretaceous, unlike many other marine turtles that went extinct.

These findings extend the known evolutionary history for the Peritresius clade to include two anatomically distinct species from the Late Cretaceous epoch, and also reveal that Peritresius was distributed across a wider region than previously thought.

Drew Gentry says: “This discovery not only answers several important questions about the distribution and diversity of sea turtles during this period but also provides further evidence that Alabama is one of the best places in the world to study some of the earliest ancestors of modern sea turtles.”

Advertisements

Early dinosaurs, gay vultures, other recent science


This video says about itself:

18 April 2018

The early dinosaurs seem to owe much of their success to an extinction event, a new study finds, and a gay griffon vulture couple have successfully raised a chick that has now been released. All this and more in this week’s 7 Days of Science.

Shark evolution video


This video says about itself:

A timeline Of SHARK EVOLUTION (prehistoric till present day)

12 April 2018

Sharks are 450 million years old and have been on this planet longer than almost any other animal. They have lived through every major mass extinction event and have survived long past many of their competitors. With over 3,000 species spanning nearly half a billion years, sharks are one of the most evolutionarily successful animals to ever live. Tracking their evolutionary history, we can learn about these amazing species and how they came to their modern forms.

Most of the sharks on the planet have developed in the Cenozoic era, except for the truly ancient sharks from the Cretaceous period. The newest shark species to enter the water is the Hammerhead Shark. Hammerhead Shark evolution only dates back about 20 million years. Currently there are around 440 species of shark swimming in our oceans, however every year scientists are finding more unique species.

Time line of shark evolution

1. 514 million years ago : Metaspriginna was the oldest known fish-a sector of all jawed vertebrates.
2. 370 million years ago : Cladoselache was the earliest and most well-known shark. Its jaw was fused to its head.
3. 330 million years ago : Falcaus had a dorsal spine and large eyes w.r.t to its tiny body.
4. 320 million years ago : Stetacanthus had tooth-like skin preventing injury
5. 290 million years ago : Helicoprion had a jaw curved into a swirl shape. By this time sharks were able to grow teeth faster.
6. 180 million years ago : Hybodus had extremely sharp canine teeth and flat grinders in the back like a modern day bull shark.
7. 100 million years ago : Ginsu shark was one of the most modern sharks of its time.
8. 55 million years ago : Otodus was huge (30ft-39ft in length). It was the earliest known relative of all mackerel sharks.
9. 15.9 million years ago : Megalodon, meaning BIG TOOTH was one of the largest and fiercest predators ever. Fossil remains of megalodon suggest that this giant shark reached a length of about 59+ ft.

Fossil baleen whale discovery in New Zealand


This video says about itself:

36.4M-Year-Old Fossilized Skeleton May Be Oldest Baleen Whale Relative

12 May 2017

Whale fossil found in Peru is the oldest-known baleen whale relative ever discovered, according to research published May 11 in Current Biology.

From the University of Otago in New Zealand:

New genus and species of extinct baleen whale identified

April 18, 2018

University of Otago palaeontologists are rewriting the history of New Zealand’s ancient whales by describing a previously unknown genus of baleen whale, alive more than 27.5 million years ago and found in the Hakataramea Valley.

The new genus and species of extinct baleen whale is based on a skull and associated bones unearthed from the Kokoamu Greensand, a noted fossil-bearing rock unit in the South Canterbury and Waitaki district from the Oligocene period, which extends from about 33.9 million to 23 million years ago. At this time, New Zealand was an archipelago surrounded by shallow, richly productive seas.

Former PhD student in the University of Otago’s Department of Geology, Cheng-Hsiu Tsai and his supervisor, Professor Ewan Fordyce, have named the new genus Toipahautea waitaki, which translates in Māori as a baleen-origin whale from the Waitaki region.

Professor Fordyce says the discovery is significant in New Zealand’s fossil history.

“This is a pretty old whale that goes almost half-way back to the age of the dinosaurs. We are tracking whale history back through time”, Professor Fordyce explains.

“This newly-named whale lived about 27.5 million years ago. It’s about as old a common ancestor as we have for the living baleen whales like the minke whales and the right whales.”

Baleen whales are a group of Mysticeti, large whales usually from colder waters that lack teeth but have baleen plates in the upper jaw which are used to filter food such as krill out of large quantities of seawater.

The fossil was actually recovered from the Hakataramea Valley in South Canterbury 30 years ago in January 1988. However, it was only worked up in recent years with Dr Tsai — who is now currently working at the National Taiwan University — beginning his thesis only a few years ago. The thesis provided the analytical framework to identify and name the new whale.

The research paper announcing the new archaic baleen whale was published today in the scientific journal Royal Society Open Science.

While the skeleton of the whale was disarticulated when it was excavated, the bones were closely associated, which gave the palaeontologists plenty of material to work with. In particular, the highly diagnostic earbones were preserved, helping with identification.

The skull was about one metre long and the body about five metres, which means it was a reasonably small species, Professor Fordyce says. “That’s about half the size of an adult minke whale.”

It was previously known that the baleen whales can take on board thousands of litres of water in the lower jaws which they scoop open to get great mouthfuls of water and food. Toipahautea waitaki’s jaws were toothless, long and narrow, Professor Fordyce says, suggesting that it fed in a similar way to the modern-day minke whales.

The researchers were not able to determine how this whale died. Professor Fordyce says it could have been attacked by a shark, stranded on a beach or died of disease. When it died, it sank to the bottom of the sea floor with its skeleton falling apart and becoming a hub for coral and other organisms to grow on.

Professor Fordyce expects the ancient whales’ history books may keep being rewritten in years to come.

“We are pretty sure there are some species [of baleen whale] that will be older than these. But right now it anchors the modern baleen whale lineage to at least 27.5 million years.”

The Toipahautea waitaki fossil was collected during fieldwork funded by a grant from the National Geographic Society with further lab work also funded by the Society.

Dinosaurs extinct, fish survived


This 2017 video is called Fish | Educational Video for Kids.

From the University of California – Los Angeles in the USA:

Marine fish won an evolutionary lottery 66 million years ago

The rapid proliferation of acanthomorphs was a response to a mass extinction

April 17, 2018

Why do our oceans contain such a staggering diversity of fish of so many different sizes, shapes and colors? A UCLA-led team of biologists reports that the answer dates back 66 million years, when a six-mile-wide asteroid crashed to Earth, wiping out the dinosaurs and approximately 75 percent of the world’s animal and plant species.

Slightly more than half of today’s fish are “marine fish“, meaning they live in oceans. And most marine fish, including tuna, halibut, grouper, sea horses and mahi-mahi, belong to an extraordinarily diverse group called acanthomorphs. (The study did not analyze the large numbers of other fish that live in lakes, rivers, streams, ponds and tropical rainforests.)

The aftermath of the asteroid crash created an enormous evolutionary void, providing an opportunity for the marine fish that survived it to greatly diversify.

“Today’s rich biodiversity among marine fish shows the fingerprints of the mass extinction at the end of the Cretaceous period“, said Michael Alfaro, a professor of ecology and evolutionary biology in the UCLA College and lead author of the study.

To analyze those fingerprints, the “evolutionary detectives” employed a new genomics research technique developed by one of the authors. Their work is published in the journal Nature Ecology and Evolution.

When they studied the timing of the acanthomorphs’ diversification, Alfaro and his colleagues discovered an intriguing pattern: Although there were many other surviving lineages of acanthomorphs, the six most species-rich groups of acanthomorphs today all showed evidence of substantial evolutionary change and proliferation around the time of the mass extinction. Those six groups have gone on to produce almost all of the marine fish diversity that we see today, Alfaro said.

He added that it’s unclear why the other acanthomorph lineages failed to diversify as much after the mass extinction.

“The mass extinction, we argue, provided an evolutionary opportunity for a select few of the surviving acanthomorphs to greatly diversify, and it left a large imprint on the biodiversity of marine fishes today”, Alfaro said. “It’s like there was a lottery 66 million years ago, and these six major acanthomorph groups were the winners.”

The findings also closely match fossil evidence of acanthomorphs’ evolution, which also shows a sharp rise in their anatomical diversity after the extinction.

The genomic technique used in the study, called sequence capture of DNA ultra-conserved elements, was developed at UCLA by Brant Faircloth, who is now an assistant professor of biological sciences at Louisiana State University. Where previous methods used just 10 to 20 genes to create an evolutionary history, Faircloth’s approach creates a more complete and accurate picture by using more than 1,000 genetic markers. (The markers include genes and other DNA components, such as parts of the DNA that turn proteins on or off, and cellular components that play a role in regulating genes.)

The researchers also extracted DNA from 118 species of marine fish and conducted a computational analysis to determine the relationships among them. Among their findings: It’s not possible to tell which species are genetically related simply by looking at them. Seahorses, for example, look nothing like goatfish, but the two species are evolutionary cousins — a finding that surprised the scientists.

“We demonstrate this approach works, and that it sheds new light on evolutionary history for the most species-rich group of marine vertebrates”, Alfaro said.

Marine animals discoveries off Indonesia


This video says about itself:

Diving in Bali is a document of an extraordinary expedition I made to Indonesia’s magical island of Bali in 2006 with Aquamarine Diving.

From Tulamben’s awesome USAT Liberty wreck, to the reef manta rays of Nusa Penida, via the fascinating macro marine life of Tulamben and Seraya Secrets, the footage covers the breadth of Bali’s fascinating underwater world.

The video features 158 species of marine life, and their common and scientific names are available by turning on the captions with the CC button under the video.

Viewers can now contribute subtitles for the marine life names in this video in many languages. Find out more here.

From Tulamben there is footage of the wreck of the USAT Liberty in both day time and night time, including the humphead parrotfish that spend the night there. Also from Tulamben are numerous marine live encounters from dives at the Drop-Off and the Coral Garden.

Just around the corner we make a dive at Seraya Secrets, a macro hotspot where I encountered seahorses and nudibranchs. From Padangbai on the east coast of Bali we have footage from The Blue Lagoon and Pura Jepun. From the island of Nusa Penida we have the manta ray cleaning station, Manta Point, and Ped.

From the National University of Singapore:

More than 12,000 marine creatures uncovered during West Java deep-sea exploration

Over a dozen new species of crabs, prawns and lobsters discovered; over 40 new records for Indonesia

April 17, 2018

Despite a stormy start thanks to Cyclone Marcus, scientists who participated in the South Java Deep Sea Biodiversity Expedition 2018 (SJADES 2018) had collected more than 12,000 creatures during their 14-day voyage to survey the unexplored deep seas off the southern coast of West Java, Indonesia.

The expedition team, consisting 31 researchers and support staff, were led by Professor Peter Ng, Head of the Lee Kong Chian Natural History Museum of the National University of Singapore (NUS), and Professor Dwi Listyo Rahayu, Senior Research Scientist at the Research Center for Oceanography (RCO) of the Indonesian Institute of Sciences (LIPI). The NUS research team comprises scientists from the Lee Kong Chian Natural History Museum and the Tropical Marine Science Institute.

Some 800 species from over 200 families of sponges, jellyfish, molluscs, starfish, urchins, worms, crabs, prawns and fish were uncovered during the expedition. Over a dozen new species of hermit crabs, prawns, lobsters and crabs were discovered, and over 40 species of various kinds are new records for Indonesia.

Among the deep-sea creatures new to science is a crab that has fuzzy spines and blood-red eyes; a lobster with long arms and zebra-patterned shell; and a hermit crab with green eyes and orange banded pincers. …

63 stations sampled within a fortnight

The research team departed Muara Baru, Jakarta in Indonesia on 23 March 2018 on board Indonesian research vessel Baruna Jaya VIII. They sailed anti-clockwise towards Cilacap in southern Java and back, covering a total distance of 2,200 kilometres.

“14 days of shared challenges at sea has enabled us to forge strong ties with our Indonesian collaborators, and such links are important to the long-term scientific ties between our two countries,” said Prof Ng, chief scientist for the Singapore team. “On the research front, our teams have learnt a lot about how to conduct deep-sea science, handle the various equipment needed for such work, and had the opportunity to sample and examine a multitude of fantastic deep sea animals. We expect to identify more new species among the pickings of the expedition, and we certainly look forward to studying the specimens and data with our Indonesian friends.”

Prof Rahayu, chief scientist for the Indonesia team, said, “The Indonesian scientists benefitted both personally and professionally through this expedition, which was partly a capacity-building exercise for our young scientists. Through interacting with international scientists, they were exposed to new scientific techniques and methodologies in an environment that presents a different set of challenges from their own scientific specialities. Hopefully, such knowledge transfer and collaboration would build stronger and more resilient ties among between our two nations.”

About the expedition

The South Java Deep-Sea Biodiversity Expedition 2018 is the first concerted deep-sea biological exploration conducted by Singapore and Indonesia, to study deep-sea marine life in the largely unexplored part of the waters off the southern coast of West Java.

This unprecedented project is a reflection of the bold and collaborative spirit embodied in RISING50 — a celebration of 50 years of diplomatic relations between Singapore and Indonesia. This joint initiative reaffirms the depth and diversity of the long-standing collaboration between the academic and scientific communities of Singapore and Indonesia.

The samples collected will be studied by scientists from both countries. This is anticipated to take up to two years, and the results will be shared and discussed with the world at a special workshop that will be held in Indonesia in 2020. The outputs will then be collated and published in the museum’s science-citation journal, The Raffles Bulletin of Zoology.

Expedition results