Wasps killing cockroaches 25 million years ago

This 2011 video is about the ensign wasp Evania appendigaster.

From Oregon State University in the USA:

Salute the venerable ensign wasp, killing cockroaches for 25 million years

September 28, 2020

An Oregon State University study has identified four new species of parasitic, cockroach-killing ensign wasps that became encased in tree resin 25 million years ago and were preserved as the resin fossilized into amber.

“Some species of ensign wasps have even been used to control cockroaches in buildings,” OSU researcher George Poinar Jr. said. “The wasps sometimes are called the harbingers of cockroaches — if you see ensign wasps you know there are at least a few cockroaches around. Our study shows these wasps were around some 20 or 30 million years ago, with probably the same behavioral patterns regarding cockroaches.”

Ensign wasps, of the Hymenoptera order and scientifically known as Evaniidae, earned their common name because their abdomen resembles a flag; an ensign is a large flag on a ship, usually flown at the stern or rear of the vessel, that indicates the ship’s nationality.

“As the wasps move about, their ‘ensign’ is constantly moving up and down as if they are flag-waving,” said Poinar, professor emeritus in the OSU College of Science and an international expert in using plant and animal life forms trapped in amber to learn more about the biology and ecology of the distant past.

About 400 species of ensign wasps exist today, distributed across 20 genera. The wasps live everywhere except polar regions. They typically measure 5 to 7 millimeters in length and don’t sting or bite but are lethal for unhatched cockroaches.

A female ensign wasp will look for cockroach egg cases, known as ootheca, and lay an egg on or in one of the cockroach eggs inside the case. When the wasp egg hatches, the larva eats the cockroach egg where it was laid.

Successive instars of the larva then consume the other dozen or so eggs inside the cockroach egg case. Mature wasp larvae pupate within the cockroach egg case en route to coming out as adults, and no cockroach offspring emerge from an egg case infiltrated by an ensign wasp.

Analyzing Tertiary period specimens from Dominican amber, Poinar was able to describe three new species of ensign wasps: Evaniella setifera, Evaniella dominicana and Semaeomyia hispaniola. He described a fourth, Hyptia mexicana, from Mexican amber. The Tertiary period began 65 million years ago and lasted for more than 63 million years.

No cockroaches accompanied the wasps in the amber, but three flying termites were found along with an ensign wasp in one of the Dominican amber pieces. It’s likely the termites were sharing a nest with the cockroaches and this attracted the wasp, Poinar said.

Oligocene prehistoric dolphin discovery

This 9 July 2020 video says about itself:

A giant 16-foot long dolphin has been discovered. It lived 25 million years ago. It feasted on … whales and it was the apex predator of the ocean

Researchers found a full skeleton of a cetacean called Ankylorhiza tiedemani. It shared many similar features with both baleen whales and modern toothed whales. This dolphin had tusk-like front teeth. It lived in present-day South Carolina. Fossil evidence includes skull anatomy and teeth, a flipper and its vertebral column. It revealed that this large dolphin was a ‘top predator’ in the community. It was very clearly preying upon large-bodied prey like a killer whale.

Ankylorhiza was a ruthless ‘ecological specialist’ when it came to hunting. At about 16 feet long, it was about twice the size of average-sized dolphins. Ankylorhiza has proportionally large teeth with thickened roots. It is an adaptation for higher bite force. The teeth have longitudinal ridges which cut through flesh more efficiently. It is also believed to be the first marine animal that used echolocation. It used sound to obtain information about surroundings and to find food.

From ScienceDaily:

15-foot-long skeleton of extinct dolphin suggests parallel evolution among whales

July 9, 2020

A report in the journal Current Biology on July 9 offers a detailed description of the first nearly complete skeleton of an extinct large dolphin, discovered in what is now South Carolina. The 15-foot-long dolphin (Ankylorhiza tiedemani comb. n.) lived during the Oligocene — about 25 million years ago — and was previously known only from a partial rostrum (snout) fossil.

The researchers say that multiple lines of evidence — from the skull anatomy and teeth, to the flipper and vertebral column — show that this large dolphin (a toothed whale in the group Odontoceti) was a top predator in the community in which it lived. They say that many features of the dolphin’s postcranial skeleton also imply that modern baleen whales and modern toothed whales must have evolved similar features independently, driven by parallel evolution in the very similar aquatic habitats in which they lived.

“The degree to which baleen whales and dolphins independently arrive at the same overall swimming adaptations, rather than these traits evolving once in the common ancestor of both groups, surprised us,” says Robert Boessenecker of the College of Charleston in Charleston, South Carolina. “Some examples include the narrowing of the tailstock, increase in the number of tail vertebrae, and shortening of the humerus (upper arm bone) in the flipper.

“This is not apparent in different lineages of seals and sea lions, for example, which evolved into different modes of swimming and have very different looking postcranial skeletons,” he adds. “It’s as if the addition of extra finger bones in the flipper and the locking of the elbow joint has forced both major groups of cetaceans down a similar evolutionary pathway in terms of locomotion.”

Though first discovered in the 1880s from a fragmentary skull during phosphate dredging of the Wando River, the first skeleton of Ankylorhiza was discovered in the 1970s by then Charleston Museum Natural History curator Albert Sanders. The nearly complete skeleton described in the new study was found in the 1990s. A commercial paleontologist by the name of Mark Havenstein found it during construction of a housing subdivision in South Carolina. It was subsequently donated to the Mace Brown Museum of Natural History, to allow for its study.

While there’s much more to learn from this fossil specimen, the current findings reveal that Ankylorhiza was an ecological specialist. The researchers say the species was “very clearly preying upon large-bodied prey like a killer whale.”

Another intriguing aspect, according to the researchers, is that Ankylorhiza is the first echolocating whale to become an apex predator. When Ankylorhiza became extinct by about 23 million years ago, they explain, killer sperm whales and the shark-toothed dolphin Squalodon evolved and reoccupied the niche within 5 million years. After the last killer sperm whales died out about 5 million years ago, the niche was left open until the ice ages, with the evolution of killer whales about 1 or 2 million years ago.

“Whales and dolphins have a complicated and long evolutionary history, and at a glance, you may not get that impression from modern species,” Boessenecker says. “The fossil record has really cracked open this long, winding evolutionary path, and fossils like Ankylorhiza help illuminate how this happened.”

Boessenecker notes that more fossils of Ankylorhiza are awaiting study, including a second species and fossils of Ankylorhiza juveniles that can offer insight into the dolphin’s growth. He says that there’s still much to learn from fossilized dolphins and baleen whales from South Carolina.

“There are many other unique and strange early dolphins and baleen whales from Oligocene aged rocks in Charleston, South Carolina,” Boessenecker says. “Because the Oligocene epoch is the time when filter-feeding and echolocation first evolved, and since marine mammal localities of that time are scarce worldwide, the fossils from Charleston offer the most complete window into the early evolution of these groups, offering unparalleled evolutionary insight.”

New extinct giant wombat discovery in Australia

This 25 June 2020 video says about itself:

A new extinct family of giant wombat relatives has been discovered in the Australian desert. The giant marsupial that roamed prehistoric Australia 25 million years ago is so different from its wombat cousins that scientists have had to create a new family to accommodate it.

This 27 June 2020 video says about itself:

A MEGA-WOMBAT the size of a bear that lived around 25million years ago has been unearthed. Scientists discovered the massive beast after digging up part of its skull and bones in Lake Pinpa, Australia.

The animal has been named Mukupirna nambensis – with the first part of its name meaning “big bones”. It weighed up to 171kg and was at least four times larger than all currently living wombats – bigger than a giant panda.

The animal has been classed as an entirely new species and is a member of a group of animals called Vombatiformes. The family also includes creatures such as koalas, modern wombats and their ancient relatives.

Scientists have said the discovery increases our understanding of how wombats developed digging and burrowing behaviour. Its teeth show it only ate plants and its arms suggest it would scratch for food on the ground, such as when looking for roots. Despite its massive size, however, it is not even the biggest wombat-like creature every found. Diprotodon has that honour, weighing in at an impressive 2,000kg – two tonnes – and surviving until at least 50,000 years ago.

Dr Robin Beck, from The University of Salford, who led the study, said: “Koalas and wombats are amazing animals. “But animals like Mukupirna show that their extinct relatives were even more extraordinary, and many of them were giants.” He added: “It tells us a lot about the evolution of wombats, koalas and their relatives. “It is remarkable for its large size – this was clearly an impressive, powerful beast.”

The bones were discovered after drought and strong winds blew the surface of the dry salt lake bed. The freak conditions uncovered the remains of animals that died after getting stuck in the mud millions of years ago. Archaeologists used an “acupuncture” method to find the bones, pushing metal rods into the soft mud until they hit something hard before digging it up.

Mukupirna is now the closest known relative of modern wombats, yet it is still so different scientists have given it its own family of creatures – Mukupirnidae. It is likely the mega wombat vanished during a global climate shift which saw its scrubby forest home vanish. Lusher and more diverse forests followed, which will have lead to climate conditions not suited for the Mukupirnids.

Professor Michael Archer of the University of New South Wales, who was part of the team that first uncovered the bones which have only just been identified in 1975, hailed it as a “mysterious new beast”. Julien Louys of Griffith University, who co-authored the study, said: “The description of this new family fills a crucial missing piece to the ancient bestiary of Australia. “It joins other weird and extinct marsupials from 25 million years ago, many of which we wouldn’t recognise today.”

Prehistoric monkeys from Africa to South America

This 10 April 2020 video says about itself:

A crew of now-extinct monkeys made a treacherous transatlantic journey on a natural raft from Africa to settle in South America around 35 million years ago, according to a study of fossilized teeth found in Peru.

It’s believed the prehistoric Ucayalipithecus monkeys made the more than 900-mile trip across the Atlantic (a narrower ocean at the time) on floating islands of vegetation that broke off from coastlines, possibly during a tropical storm.

From the Keck School of Medicine of USC in the USA:

Ancient teeth from Peru hint now-extinct monkeys crossed Atlantic from Africa

April 9, 2020

Four fossilized monkey teeth discovered deep in the Peruvian Amazon provide new evidence that more than one group of ancient primates journeyed across the Atlantic Ocean from Africa, according to new USC research just published in the journal Science.

The teeth are from a newly discovered species belonging to an extinct family of African primates known as parapithecids. Fossils discovered at the same site in Peru had earlier offered the first proof that South American monkeys evolved from African primates.

The monkeys are believed to have made the more than 900-mile trip on floating rafts of vegetation that broke off from coastlines, possibly during a storm.

“This is a completely unique discovery,” said Erik Seiffert, the study’s lead author and Professor of Clinical Integrative Anatomical Sciences at Keck School of Medicine of USC. “It shows that in addition to the New World monkeys and a group of rodents known as caviomorphs — there is this third lineage of mammals that somehow made this very improbable transatlantic journey to get from Africa to South America.”

Researchers have named the extinct monkey Ucayalipithecus perdita. The name comes from Ucayali, the area of the Peruvian Amazon where the teeth were found, pithikos, the Greek word for monkey and perdita, the Latin word for lost.

Ucayalipithecus perdita would have been very small, similar in size to a modern-day marmoset.

Dating the migration

Researchers believe the site in Ucayali where the teeth were found is from a geological epoch known as the Oligocene, which extended from about 34 million to 23 million years ago.

Based on the age of the site and the closeness of Ucayalipithecus to its fossil relatives from Egypt, researchers estimate the migration might have occurred around 34 million years ago.

“We’re suggesting that this group might have made it over to South America right around what we call the Eocene-Oligocene Boundary, a time period between two geological epochs, when the Antarctic ice sheet started to build up and the sea level fell,” said Seiffert. “That might have played a role in making it a bit easier for these primates to actually get across the Atlantic Ocean.”

An improbable discovery

Two of the Ucayalipithecus perdita teeth were identified by Argentinean co-authors of the study in 2015 showing that New World monkeys had African forebears. When Seiffert was asked to help describe these specimens in 2016, he noticed the similarity of the two broken upper molars to an extinct 32 million-year-old parapithecid monkey species from Egypt he had studied previously.

An expedition to the Peruvian fossil site in 2016 led to the discovery of two more teeth belonging to this new species. The resemblance of these additional lower teeth to those of the Egyptian monkey teeth confirmed to Seiffert that Ucayalipithecus was descended from African ancestors.

“The thing that strikes me about this study more than any other I’ve been involved in is just how improbable all of it is,” said Seiffert. “The fact that it’s this remote site in the middle of nowhere, that the chances of finding these pieces is extremely small, to the fact that we’re revealing this very improbable journey that was made by these early monkeys, it’s all quite remarkable.”

Apes and monkeys evolution, new research

This 2008 video is called Aegyptopithecus Mandible Fragments.

From the American Museum of Natural History in the USA:

Fossil suggests apes, old world monkeys moved in opposite directions from shared ancestor

Hip joint study could help explain why apes, humans, and Old World monkeys move so differently

In terms of their body plan, Old World monkeys — a group that includes primates like baboons and macaques — are generally considered more similar to ancestral species than apes are. But a new study that analyzes the first well-preserved femur of Aegyptopithecus zeuxis, a common ancestor of Old World monkeys and apes, suggests that as far as locomotion goes, apes and Old World monkeys each evolved a way of moving that was different from the ancestral species as they adapted to different niches in their environments.

“Our study shows that Aegyptopithecus preserves an ancient hip morphology not present in living anthropoid primates,” said Sergio Almécija, a paleoanthropologist and evolutionary biologist in the Division of Anthropology at the American Museum of Natural History who is first author on the study, which was published in Nature Communications this week. “As far as the hip is concerned, it seems that apes, humans, and Old World monkeys have all parted ways long ago — which would explain why they move around so differently today.”

The fossil analyzed in the study was discovered in 2009 and is the most complete femur of Aegyptopithecus, a 15-lb (7-kg) likely tree-dwelling species that lived in Egypt about 30 million years ago, close to the time when hominoids (the group that includes apes and humans) split from the larger group that includes Old World monkeys. A well-preserved femur allowed researchers to glean details about the hip joint, a major anatomical region for inferring locomotion, using a combination of 3D morphometric analysis and evolutionary modeling.

For the analysis, the authors compared the fossil bone to other extinct and modern species, including humans, chimpanzees, and Victoriapithecus and Homunculus (extinct Old World and New World monkeys, respectively). The evolutionary modeling analysis used in the study included a method that was developed to identify convergent evolution in anole lizards in the Caribbean, which have independently developed comparable niche-specific adaptations across various islands.

The results indicate that the ancestral hip joint is, from an evolutionary perspective, as far from the hip joint of modern Old World monkeys as from those of the great apes — suggesting that each group evolved a distinct way of moving as they specialized for success in different environmental niches.

In addition, evolutionary modeling suggests that living great apes — including orangutans, chimpanzees, and gorillas — may have independently developed similar hip joint anatomy that allows wide-ranging, flexible movement through their arboreal habitats.

“What I find really exciting about the modeling approach is that we can develop better hypotheses about what drove the divergence of apes and monkeys, and the emerging picture is that navigating the environment is one of the key factors,” said Ashley Hammond, assistant curator in the Division of Anthropology and an author on the study.

Invertebrate fossils discovery in Dominican Republic amber

From Oregon State University in the USA:

Meet the ‘mold pigs,’ a new group of invertebrates from 30 million years ago

October 8, 2019

Fossils preserved in Dominican amber reveal a new family, genus and species of microinvertebrate from the mid-Tertiary period, a discovery that shows unique lineages of the tiny creatures were living 30 million years ago.

The findings by George Poinar Jr. of the Oregon State University College of Science give a rare look at a heretofore unknown clade of invertebrates, along with their fungal food source and other animals that lived in their habitat.

Poinar, an international expert in using plant and animal life forms preserved in amber to learn more about the biology and ecology of the distant past, informally calls the new animals “mold pigs” for their resemblance to swine, and their diet. Scientifically, they are Sialomorpha dominicana, from the Greek words for fat hog (sialos) and shape (morphe).

Invertebrate means not having a backbone, and invertebrates account for roughly 95 percent of animal species.

“Every now and then we’ll find small, fragile, previously unknown fossil invertebrates in specialized habitats,” Poinar said. “And occasionally, as in the present case, a fragment of the original habitat from millions of years ago is preserved too. The mold pigs can’t be placed in any group of currently existing invertebrates — they share characteristics with both tardigrades, sometimes referred to as water bears or moss pigs, and mites but clearly belong to neither group.”

The several hundred individual fossils preserved in the amber shared warm, moist surroundings with pseudoscorpions, nematodes, fungi and protozoa, Poinar said.

“The large number of fossils provided additional evidence of their biology, including reproductive behavior, developmental stages and food,” he said. “There is no extant group that these fossils fit into, and we have no knowledge of any of their descendants living today. This discovery shows that unique lineages were surviving in the mid-Tertiary.”

The Tertiary period began 65 million years ago and lasted for more than 63 million years.

About 100 micrometers long, the mold pigs had flexible heads and four pairs of legs. They grew by molting their exoskeleton and fed mainly on fungi, supplementing that food source with small invertebrates.

“No claws are present at the end of their legs as they are with tardigrades and mites,” Poinar said. “Based on what we know about extant and extinct microinvertebrates, S. dominicana appears to represent a new phylum. The structure and developmental patterns of these fossils illustrate a time period when certain traits appeared among these types of animals. But we don’t know when the Sialomorpha lineage originated, how long it lasted, or whether there are descendants living today.”

Marine animals revolution after dinosaur extinction

This 2015 video from the USA says about itself:

What the heck is a crinoid? They might be one of the most common fossils this side of the Rocky mountains but they are seriously cool.

From the British Antarctic Survey:

Major shift in marine life occurred 33 million years later in the South

May 17, 2018

A new study of marine fossils from Antarctica, Australia, New Zealand and South America reveals that one of the greatest changes to the evolution of life in our oceans occurred more recently in the Southern Hemisphere than previously thought. The results are published today (17 May 2018) in the journal Communications Biology.

The Marine Mesozoic Revolution (MMR) is a key theory in evolutionary history. While dinosaurs ruled the land, profound changes occurred in the shallow seas that covered the Earth.

During the Mesozoic, around 200 million years ago, marine predators evolved that could drill holes and crush the shells of their prey. And although small in comparison to dinosaurs, these new predators, including crustacea and some types of modern fish, had a dramatic impact on marine life.

Among the species most heavily affected were sea lilies or isocrinids — invertebrates tethered to the seafloor by graceful stalks. Side on, these stalks resemble a vertebral column; in cross section, they are shaped like a five-pointed star — because sea lilies are related to starfish, sea urchins, and sand dollars. At their height during the Paleozoic, forests of sea lilies carpeted seafloors the world over.

Their restricted ability to move made sea lilies vulnerable to the new predators, so during the MMR they were forced into deeper waters in order to survive. Because it marked such a radical change in marine communities, scientists have long sought to understand this shift. They believed it occurred around 66 million years ago, but this new study shows that in the Southern Hemisphere, sea lilies remained in shallow waters until much more recently — around 33 million years ago.

A team from British Antarctic Survey, the University of Cambridge, the University of Western Australia, and the Royal Botanic Gardens, Victoria, made the discovery when they brought together field samples from Antarctica and Australia, with fossils from museum collections for the first time. The study provides conclusive evidence that this change happened at different times in different parts of the globe, and in the Antarctic and Australia, sea lilies hung on in shallow waters until the end of the Eocene, around 33 million years ago and it is unknown exactly why.

The study shows that knowing more about the Antarctic can reshape — or overturn — existing scientific theories.

According to lead author Dr Rowan Whittle from British Antarctic Survey: “It is surprising to see such a difference in what was happening at either end of the world. In the Northern Hemisphere these changes happened whilst the dinosaurs ruled the land, but by the time these sea lilies moved into the deep ocean in the Southern Hemisphere the dinosaurs had been extinct for over 30 million years.

“Given how the ocean is changing and projected to change in the future it is vital that we understand how different parts of the world could be affected in different ways and at a range of timescales.”

To get this richer picture of how sea lilies responded to the changing oceans of the Southern Hemisphere over millions of years, the team travelled to some of the remotest regions of Western Australia and Antarctica. Their hunt for fossil sea lilies was rewarded by the discovery of nine new species.

Co-author Dr Aaron Hunter from the University of Cambridge says: “We have documented how these sea lilies evolved as Australia split away from Antarctica moving north and becoming the arid outback we know today, while ice formed over the South Polar Region.

“The sea lilies survived in the shallow waters for millions of years longer than their Northern Hemisphere cousins, but as the continents moved further apart, they eventually had nowhere to go but the deep ocean depths where they have clung on to existence to this day.”

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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.

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Ancient dolphin species discovery in Ecuador

This video says about itself:

21 December 2017

A well-preserved juvenile skull recently discovered in Ecuador belongs to a new species of ancient dolphin, which researchers are calling Urkudelphis chawpipacha. The fossil was discovered near Montañita in Santa Elena Province, a tropical region of Ecuador, and is believed to be between 24 to 26 million years old.

From PLOS:

Ancient dolphin species Urkudelphis chawpipacha discovered in Ecuador

Small dolphin skull may have belonged to river dolphin ancestor from the Oligocene

December 22, 2017

Summary: An extinct dolphin species likely from the Oligocene has been discovered. The fossil is one of the few fossil dolphins from the equator, and is a reminder that Oligocene cetaceans may have ranged widely in tropical waters.

A new dolphin species likely from the Oligocene was discovered and described in Ecuador, according to a study published December 20, 2017 in the open-access journal PLOS ONE by Yoshihiro Tanaka from the Osaka Museum of Natural History, Japan, and colleagues.

Many marine fossils described in previous research have been from long-recognized temperate regions such as South Carolina, off the coast of Oregon, Hokkaido and New Zealand. Few equatorial and polar fossils are currently known.

While in the tropical region of Santa Elena Province, Ecuador, the authors of this study found a small dolphin skull, which they identified as representing a new species, Urkudelphis chawpipacha, based on facial features. The dolphin skull had a bone crest front and center on its face, above the eye sockets. This species stands apart from other Oligocene dolphins with its shorter and wider frontal bones located near the top of the head and the parallel-sided posterior part of its jaw. The authors also conducted a phylogenetic analysis which revealed that the new species may be the ancestor of the nearly-extinct Platanistoidea, or river dolphin, and may have lived during the Oligocene era.

The fossil is one of the few fossil dolphins from the equator, and is a reminder that Oligocene cetaceans may have ranged widely in tropical waters.

This study was supported by an UPSE project IN-P5-2016-1 for equipment at UPSE, and YT thanks support of a trip to Ecuador. This work has also been supported by the Agencia Estatal de Investigación (AEI) from Spain and the European Regional Development Fund of the European Union (CGL2016-76431-P) and the project CGL2015-68333 (MINECO/FEDER, UE).

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Dugong ancestor discovery in California

This video says about itself:

4 September 2015

“Sirenia” are an order of fully aquatic, herbivorous mammals that inhabit swamps, rivers, estuaries, marine wetlands, and coastal marine waters. Four species are living, in two families and genera. These are the dugong and manatees. Sirenia also include Steller’s sea cow, extinct since the 18th century, and a number of taxa known only from fossils. The order evolved during the Eocene, more than 50 million years ago.

From Associated Press:

Remains of ancient sea cow unearthed on California island

Nov 28, 2017

VENTURA, Calif. — Scientists say they’ve unearthed fossil remains of a sea cow that lived in the shallow waters off Southern California’s Channel Islands some 25 million years ago.

The fossil skull and rib cage were discovered this summer on Santa Rosa Island, about 50 miles northwest of Los Angeles, the National Park Service announced Tuesday.

Scientists say the remains may be from a previously unknown sea cow species but they won’t know for sure until the skull is analyzed by an expert.

Some fossilized remnants of at least from four other sea cows also were found nearby.

Sea cows are torpedo-shaped plant-eaters that graze in shallow waters and can grow up to 13 feet long. The only living species are the dugong and three types of manatee.

Two researchers from the U.S. Geological Survey found the skull and rib cage in a steep ravine while mapping earthquake faults, said Yvonne Menard of the park service. Erosion may have only recently revealed them.

“This sea cow may have only been exposed the past few years after being buried for millions of years,” said Jonathan Hoffman with the Santa Barbara Museum of Natural History, which is protecting the fossils.

“They’re embedded in rock and the top surface has been exposed,” Menard said.

That surface has been covered with plaster-impregnated bandages and burlap to protect the fossils until work to excavate them can resume in late spring, Menard said.

The work is slow because researchers need to formulate a plan to excavate in the wilderness area, Hoffman said.

Researchers hope to uncover the teeth of the sea cow, which could help determine the animal’s diet and its age when it died.

The sea cow also travelled without ever leaving home. The shallow sea floor where it died actually was located about 150 miles south, in the area of San Diego and Baja California, Hoffman said.

Over millions of years, the land moved northward with the movement of the Pacific tectonic plate and the sea floor was pushed up to nearly 1,400 feet above sea level.

See also here.

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