Showing posts with label ichthyosaur. Show all posts
Showing posts with label ichthyosaur. Show all posts

Monday 23 March 2020

YORKSHIRE ICHTHYOSAUR TAIL

Ichthyosaur Tail Section. Photo: Liam Langley
A beautiful piece of ichthyosaur tail section found on the Yorkshire Coast in 2019 by the deeply awesome Liam Langley.

Ichthyosaurus are an extinct marine reptile first described from fossil fragments found in 1699 in Wales. Shortly thereafter, fossil vertebrae were published in 1708 from the Lower Jurassic and the first member of the order Ichthyosauria to be discovered.

Over time, we discovered a number of these fossil specimens and a picture of the overall look and size began to emerge. We found fossils that ranged from quite small, just a foot or two, to well over twenty-six metres in length and resembled both modern fish and dolphins. This specimen holds a well-deserved spot of honour on Liam's mantle. The detail is tremendous and just look at that masterful prep work.

Sunday 22 March 2020

Saturday 21 March 2020

DIGITS AND PHALANGES

While they resembled fish and dolphins, Ichthyosaurs were large marine reptiles belonging to the order known as Ichthyosauria or Ichthyopterygia.

In 2018, Benjamin Kear and his team delved into a new are of study through technology that allows us to look at ichthyosaur remains at the molecular level. Their findings suggest ichthyosaurs had skin and blubber quite similar to our modern dolphins.

While ichthyosaurs evolved from land-dwelling, lung-breathing reptiles, they returned to our ancient seas and evolved into the fish-shaped creatures we find in the fossil record today. Their limbs fully transformed into flippers, sometimes containing a very large number of digits and phalanges.

Their flippers tell us they were entirely aquatic as they were not well-designed for use on land. And it was their flippers that first gave us the clue that they gave birth to live young; a find later confirmed by fossil embryo and wee baby ichy finds. They thrived during much of the Mesozoic era; based on fossil evidence, they first appeared around 250 million years ago (Ma) and at least one species survived until about 90 million years ago into the Late Cretaceous.

During the early Triassic period, ichthyosaurs evolved from a group of unidentified land reptiles that returned to the sea. They were particularly abundant in the later Triassic and early Jurassic periods before being replaced as a premier aquatic predator by another marine reptilian group, the Plesiosauria, in the later Jurassic and Cretaceous.

In the Late Cretaceous, ichthyosaurs were hard hit by the Cenomanian-Turonian anoxic event. As the deepest benthos layers of the seas became anoxic, poisoned by hydrogen sulphide, deep water marine life died off. This caused a cascade that wreaked havoc all the way up the food chain. At the end of that chain were our mighty predaceous marine reptiles.

Bounty turned to scarcity and a race for survival began. The ichthyosaurs lost that race as the last lineage became extinct. It may have been their conservative evolution as a genus when faced with a need for adaptation to the world in which they found themselves and/or being outcompeted by early mosasaurs.

There are promising discoveries coming out of strata from the Cretaceous epeiric seas of Texas, USA from Nathan E. Van Vranken. His published paper from 2017, "An overview of ichthyosaurian remains from the Cretaceous of Texas, USA," looks at ichthyosaurian taxa from the mid-Cretaceous (Albian–Cenomanian) time interval in North America with an eye to ichthyosaurian distribution and demise.

Photo: This beautifully preserved Ichthyosaur paddle with its incredible detail is from Early Jurassic (183 Million Years) deposits in the Ohmden, Posidonia Shale Formation, Baden-Württemberg, east of the Rhine, southwestern Germany.

Friday 20 March 2020

BLUE LIAS ICHTHYOSAUR

This well-preserved partial ichthyosaur was found in the Blue Lias shales by Lewis Winchester-Ellis in 2018. The vertebrae you see here are from the tail section of this marine reptile.

The find includes stomach contents which tell us a little about how this particular fellow liked to dine.

As with most of his brethren, he enjoyed fish and cephalopods. Lewis found fishbone and squid tentacle hooklets in his belly. Oh yes, these ancient cephies had grasping hooklets on their tentacles. I'm picturing them wiggling all ominously. The hooklets were the only hard parts of the animal preserved in this case as the softer parts of this ancient calamari were fully or partially digested before this ichthyosaur met his end.

Ichthyosaurus was an extinct marine reptile first described from fossil fragments found in 1699 in Wales. Shortly thereafter, fossil vertebrae were published in 1708 from the Lower Jurassic and the first member of the order Ichthyosauria to be discovered.

To give that a bit of historical significance, this was the age of James Stuart, Jacobite hopeful to the British throne. While scientific journals of the day were publishing the first vertebrae ichthyosaur finds, he was avoiding the French fleet in the Firth of Forth off Scotland. This wasn’t Bonnie Prince Charlie, this was his Dad. Yes, that far back.

The first complete skeleton was discovered in the early 19th century by Mary Anning and her brother Joseph along the Dorset Jurassic Coast. Joseph had mistakenly, but quite reasonably, taken the find for an ancient crocodile. Mary excavated the specimen a year later and it was this and others that she found that would supply the research base others would soon publish on.

Mary's find was described by a British surgeon, Sir Everard Home, an elected Fellow of the Royal Society, in 1814. The specimen is now on display at the Natural History Museum in London bearing the name Temnodontosaurus platyodon, or “cutting-tooth lizard.”

Ichthyosaurus communis
In 1821, William Conybeare and Henry De La Beche, a friend of Mary's, published a paper describing three new species of unknown marine reptiles based on the Anning's finds.

Rev. William Buckland would go on to describe two small ichthyosaurs from the Lias of Lyme Regis, Ichthyosaurus communis and Ichthyosaurus intermedius, in 1837.

Remarkable, you'll recall that he was a theologian, geologist, palaeontologist AND Dean of Westminster. It was Buckland who published the first full account of a dinosaur in 1824, coining the name, "Megalosaurus."

The Age of Dinosaurs and Era of the Mighty Marine Reptile had begun.

Ichthyosaurs have been collected in the Blue Lias near Lyme Regis and the Black Ven Marls. More recently, specimens have been collected from the higher succession near Seatown. Paddy Howe, Lyme Regis Museum geologist, found a rather nice Ichthyosaurus breviceps skull a few years back. A landslip in 2008 unveiled some ribs poking out of the Church cliffs and a bit of digging revealed the ninth fossil skull ever found of a breviceps, with teeth and paddles to boot.

Specimens have since been found in Europe in Belgium, England, Germany, Switzerland and in Indonesia. Many tremendously well-preserved specimens come from the limestone quarries in Holzmaden, southern Germany.

Ichthyosaurs ranged from quite small, just a foot or two, to well over twenty-six metres in length and resembled both modern fish and dolphins.

Dean Lomax and Sven Sachs, both active (and delightful) vertebrate paleontologists, have described a colossal beast, Shonisaurus sikanniensis from the Upper Triassic (Norian) Pardonet Formation of northeastern British Columbia, Canada, measuring 3-3.5 meters in length. The specimen is now on display in the Royal Tyrrell Museum of Palaeontology in Alberta, Canada. It was this discovery that tipped the balance in the vote, making it British Columbia's Official Fossil. Ichthyosaurs have been found at other sites in British Columbia, on Vancouver Island and the Queen Charlotte Islands (Haida Gwaii) but Shoni tipped the ballot.

The first specimens of Shonisaurus were found in the 1990s by Peter Langham at Doniford Bay on the Somerset coast of England.

Dr. Betsy Nicholls, Rolex Laureate Vertebrate Palaeontologist from the Royal Tyrrell Museum, excavated the type specimen of Shonisaurus sikanniensis over three field sessions in one of the most ambitious fossil excavations ever ventured. Her efforts from 1999 through 2001, both in the field and lobbying back at home, paid off. Betsy published on this new species in 2004, the culmination of her life’s work and her last paper as we lost her to cancer in autumn of that year.

Roy Chapman Andrews, AMNH 1928 Expedition to the Gobi Desert
Charmingly, Betsy had a mail correspondence with Roy Chapman Andrews, former director of the American Museum of Natural History, going back to the late 1950s as she explored her potential career in palaeontology. Do you recall the AMNH’s sexy paleo photos of expeditions to the Gobi Desert in southern Mongolia in China in the early 20th century? I've posted a picture here to jog your memory. Roy Chapman Andrews was the lead on that trip. The man was dead sexy. His photos are what fueled the flames of my own interest in paleo.

We've found at least 37 specimens of Shonisaurus in Triassic outcrops of the Luning Formation in the Shoshone Mountains of Nevada, USA. The finds go back to the 1920s. The specimens that may it to publication were collected by M. Wheat and C. L. Camp in the 1950s.  The aptly named Shonisaurus popularis became the Nevada State Fossil in 1984. Our Shoni got around. Isolated remains have been found in a section of sandstone in Belluno, in the Eastern Dolomites, Veneto region of northeastern Italy. The specimens were published by Vecchia et al. in 2002.

For a time, Shonisaurus was the largest ichthyosaurus known.

Move over, Shoni, as a new marine reptile find competes with the Green Anaconda (Eunectes murinus) and the Blue Whale (Balaenoptera musculus) for size at a whopping twenty-six (26) metres.

The find is the prize of fossil collector turned co-author, Paul de la Salle, who (you guessed it) found it in the lower part of the intertidal area that outcrops strata from the latest Triassic Westbury Mudstone Formation of Lilstock on the Somerset coast. He contacted Dean Lomax and Judy Massare who became co-authors on the paper.

The find and conclusions from their paper put "dinosaur" bones from the historic Westbury Mudstone Formation of Aust Cliff, Gloucestershire, UK site into full reinterpretation.

And remember that ichthyosaur the good Reverend Buckland described back in 1837, the Ichthyosaurus communis? Dean Lomax was the first to describe a wee baby. A wee baby ichthyosaur! Awe. I know, right? He and paleontologist Nigel Larkin published this adorable first in the journal of Historical Biology in 2017.

They had teamed up previously on another first back in 2014 when they completed the reconstruction of an entire large marine reptile skull and mandible in 3-D, then graciously making it available to fellow researchers and the public. The skull and braincase in question were from an Early Jurassic, and relatively rare, Protoichthyosaurus prostaxalis. The specimen had been unearthed in Warwickshire back in the 1950s. Unlike most ichthyosaur finds of this age, it was not compressed and allowed the team to look at a 3-D specimen through the lens of computerized tomography (CT) scanning.

Another superb 3-D ichthyosaur skull was found near Lyme Regis by fossil hunter-turned-entrepreneur-local David Sole and prepped by the late David Costain. I'm rather hoping it went into a museum collection as it would be wonderful to see the specimen studied, imaged, scanned and 3-D printed for all to share. Here's hoping.


Ichthyosaurus somersetensis Credit: Dean R Lomax
Lomax and Sven Sachs also published on an embryo from one of the largest ichthyosaurs known, a new species named Ichthyosaurus somersetensis.

Their paper in the ACTA Palaeontologica Polonica from 2017, describes the third embryo known for Ichthyosaurus and the first to be positively identified to species level. The specimen was collected from Lower Jurassic strata (lower Hettangian, Blue Lias Formation) of Doniford Bay, Somerset, UK and is housed in the collection of the Niedersächsisches Landesmuseum (Lower Saxony State Museum) in Hannover, Germany.

We've learned a lot about them in the time we've been studying them. We now have thousands of specimens, some whole, some as bits and pieces. Many specimens that have been collected are only just now being studied and the tools we are using to study them are getting better and better.

Link to Lomax Paper: https://journals.plos.org/plosone/article…

Link to Nathan's Paper: https://www.tandfonline.com/…/10.1080/03115518.2018.1523462…

Nicholls Paper: E. L. Nicholls and M. Manabe. 2004. Giant ichthyosaurs of the Triassic - a new species of Shonisaurus from the Pardonet Formation (Norian: Late Triassic) of British Columbia. Journal of Vertebrate Paleontology 24(4):838-849 [M. Carrano/H. Street]

Wednesday 18 March 2020

SHONISAURUS OF NEVADA

The beauties you see here are ichthyosaurs. The largest of their lineage is the genus Shonisaurus who ruled our ancient seas 217 million years ago.

At least 37 incomplete fossil specimens of the marine reptile have been found in hard limestone deposits of the Luning Formation, in far northwestern Nye County of Nevada. This formation dates to the late Carnian age of the late Triassic period when present-day Nevada and parts of the western United States were covered by an ancient ocean.

The first researcher to recognize the Nevada fossil specimens as ichthyosaurs was Siemon W. Muller of Stanford University. He had the work of Sir Richard Owen and others to build on. That being said, there are very few contenders for a species that boasts vertebrae over a foot wide and weighing in at almost 10 kg or 21 lbs. Muller contacted the University of California Museum of Paleontology at Berkeley. Surface collecting by locals continued at the site but no major excavation was planned.

Sir Richard Owen, the British biologist, comparative anatomist and paleontologist, coined the name ichthyopterygia, or "fish flippers," one hundred and fourteen years earlier, but that wee bit of scientific knowledge hadn't made its way west to the general population. The finds at Luning were still, "marine monsters."

Owen, too, was building on research going back to 1699, the very first recorded fossil fragments found of these beasties in Wales. Shortly thereafter, fossil vertebrae were published in 1708 from the Lower Jurassic.

The first complete skeleton was discovered in the early 19th century by Mary Anning and her brother Joseph along the Dorset Jurassic Coast. Mary's find was described by a British surgeon, Sir Everard Home, an elected Fellow of the Royal Society, in 1814. The specimen is now on display at the Natural History Museum in London bearing the name Temnodontosaurus platyodon, or “cutting-tooth lizard.”

In 1821, William Conybeare and Henry De La Beche, a friend of Mary's, published a paper describing three new species of unknown marine reptiles based on the Anning's finds. The Rev. William Buckland would go on to describe two small ichthyosaurs from the Lias of Lyme Regis, Ichthyosaurus communis and Ichthyosaurus intermedius. All of this early work was instrumental in aiding the researchers who would join the project at Luning.

Owen is considered to have been an outstanding naturalist with a remarkable gift for interpreting fossils. Contrary to common belief, advanced study does help with identifying fossils, but what is truly needed is a keen eye. The finds at Luning were blessed to be seen by an enthusiastic local with just that right kind of keen eye.

Almost a quarter of a century after Muller's initial reports, Dr. Charles L. Camp from UCMP received correspondence further detailing the finds from a lovely Mrs. Margaret Wheat of Fallon. She wrote to Camp in September of 1928 to say that she'd been giving the quarry section a bit of a sweep, as you do, and had uncovered a nice aligned section of vertebrae with her broom. The following year, Dr. Charles L. Camp went out to survey the finds and began working on the specimens, his first field season of many, in 1954.

Back in the 1950s, these large marine reptiles were rumoured to be "marine monsters," as the concept of an ichthyosaur was not well understood by the local townsfolk. Excitement soon hit West Union Canyon as the quarry began to reveal the sheer size of these mighty beasts. Four of the specimens were fully excavated. Most of the ichthyosaur bones were left in situ, partially because the work was tremendously difficult, and partially to allow others to see how the specimens were laid down over 200 million years ago.

Camp continued to work with Wheat at the site and brought on Sam Welles and a host of students to help with excavations. The team understood the need for protection at the site. They canvassed the Nevada Legislature to establish the Ichthyosaur Paleontological State Monument. You can see one of the Park Rangers above giving a tour within the lovely Fossil Hut building they built on the site to protect the fossils.

In 1957, the site was incorporated into the State Park System and Berlin-Ichthyosaur State Park was born. The park Twenty years later, in 1977, the population of Nevada weighed in and the Legislature designated Shonisaurus popularis as the State Fossil of Nevada. Visitors are welcome to collect fossils from the exposures of the Upper Triassic (Early Norian, Kerri Zone) of the Luning Formation, West Union Canyon, just outside Berlin-Ichthyosaur State Park.

Address: State route 844, Austin, NV 89310, United States. Area: 4.58 km². Open 24 hours;
Elevation: 6,975 ft (2,126 m); Tel: +1 775-964-2440; http://parks.nv.gov/parks/berlin-ichthyosaur

Tuesday 17 March 2020

CENOMANIAN-TURONIAN IMPACT

Ichthyosaur and Plesiosaur by Edouard Riou, 1863
During the early Triassic period, ichthyosaurs evolved from a group of unidentified land reptiles that returned to the sea. They were particularly abundant in the later Triassic and early Jurassic periods before being replaced as a premier aquatic predator by another marine reptilian group, the Plesiosauria, in the later Jurassic and Cretaceous periods.

In the Late Cretaceous, ichthyosaurs were hard hit by the Cenomanian-Turonian anoxic event. As the deepest benthos layers of the seas became anoxic, poisoned by hydrogen sulphide, deep water marine life died off. This caused a cascade that wreaked havoc all the way up the food chain. At the end of that chain were our mighty predaceous marine reptiles.

Bounty turned to scarcity and a race for survival began. The ichthyosaurs lost that race as the last of their lineage became extinct. It may have been their conservative evolution as a genus when faced with a need for adaptation to the world in which they found themselves and/or being outcompeted by early mosasaurs.

Tuesday 11 February 2020

MIDDLE TRIASSIC HUMBOLDT RANGE

Looking out over the Middle Triassic exposures of the Humboldt Mountain Range.

These hills were the site of the 1905 Expedition of the University of California’s Department of Geology in Berkeley funded by the beautiful and bold, Annie Alexander, the women to whom the UCMP owes both its collection and existence. Annie brought together a paleontological crew to explore these localities and kept an expedition journal of their trip which is now on display at the University of California Museum of Paleontology at Berkeley.

Annie's interest was the ichthyosaurs and she was well pleased with the results. They dodged rattlesnakes and tarantulas, finding many new specimens as they opened up new quarries in the hills of the Humboldt Range of Nevada.

Ichthyosaurs range from quite small, just a foot or two, to well over twenty-six metres in length and resembled both modern fish and dolphins. The specimens from Nevada are especially large and well-preserved. They hail from a time, some 217 million years ago, when Nevada, and parts of the western USA, was covered by an ancient ocean that would one day become our Pacific Ocean. Many ichthyosaur specimens have come out of Nevada. So many, in fact, that they named it their State Fossil back in 1977.

Fossil fragments and complete specimens of these marine reptiles have been collected in the Blue Lias near Lyme Regis and the Black Ven Marls. More recently, specimens have been collected from the higher succession near Seatown. Paddy Howe, Lyme Regis Museum geologist, found a rather nice Ichthyosaurus breviceps skull a few years back. A landslip in 2008 unveiled some ribs poking out of the Church cliffs and a bit of digging revealed the ninth fossil skull ever found of a breviceps, with teeth and paddles to boot.

Specimens have since been found in Europe in Belgium, England, Germany, Switzerland and in Indonesia. Many tremendously well-preserved specimens come from the limestone quarries in Holzmaden, southern Germany.

Saturday 26 October 2019

MARINE REPTILES OF THE HUMBOLDTS

A very well preserved ichthyosaur block with three distinct vertebrae and some ribs just peeking out. You can see the edges of the ribs nicely outlined against the matrix.

Ichthyosaurs are an extinct order of marine reptiles from the Mesozoic era. They evolved from land-dwelling, lung-breathing reptiles, they returned to our ancient seas and evolved into the fish-shaped creatures we find in the fossil record today.

They were visibly dolphin-like in appearance but seem to share some other qualities as well. These lovelies were warm-blooded and used their coloration as camouflage. The smaller of their lineage to avoid being eaten and the larger to avoid being seen by prey. Ichthyosaurs also had insulating blubber, a lovely adaptation to keep them warm in cold seas.

Over time, their limbs fully transformed into flippers, sometimes containing a very large number of digits and phalanges. Their flippers tell us they were entirely aquatic as they were not well-designed for use on land. And it was their flippers that first gave us the clue that they gave birth to live young; a hypothesis later confirmed by fossil embryo and wee baby ichy specimens.

We find their fossil remains in outcrops spanning from the mid-Cretaceous to the earliest Triassic. As we look through the fossils, we see a slow evolution in body design moving towards that enjoyed by dolphins and tuna by the Upper Triassic, albeit with a narrower, more pointed snout. During the early Triassic period, ichthyosaurs evolved from a group of unidentified land reptiles that returned to the sea. They were particularly abundant in the later Triassic and early Jurassic periods before being replaced as a premier aquatic predator by another marine reptilian group, the Plesiosauria, in the later Jurassic and Cretaceous periods.

The block you see here is from Middle Triassic (Anisian/Ladinian) outcrops in the West Humboldt Mountains, Nevada.

Friday 25 October 2019

SUNRISE FORMATION, NEVADA

At the entrance to the Pliensbachian-Toarcian localities at Joker Peak and Mina Peak Members of the Sunrise Formation, Nevada, USA.

The ammonites of this section were first studied by Dr. Paul Smith, past Chair of Earth and Ocean Sciences, University of British Columbia and more recently by Andrew Caruthers et al.

Caruthers and his team also took a goodly look at the Early Jurassic coral fauna. Caruthers is an interesting cat. He uses a combination of invertebrate paleontology and isotope geochemistry to ponder the effects of paleoclimate change and mass extinction. He's turned his eye in recent years to the Paleozoic of the Michigan Basin AND he's based in Kalamazoo, MI. Yep, Kalamazoo.

Others have taken up the mantle of discovery from these sites. Pengfei Hou did his 2014 Masters thesis comparing the Sinemurian (Early Jurassic) stratigraphic sections of Last Creek, British Columbia and Five Card Draw, Nevada including a detailed taxonomic study from the Involutum Zone to the lower part of the Harbledownense Zone of the Sinemurian.

Thursday 24 October 2019

DUBIOUS DAONELLA DUBIA

Triassic ammonoids, West Humboldt Mountains, Nevada, USA. This was the site of the 1905 Expedition of the University of California’s Department of Geology in Berkeley funded by the beautiful and bold, Annie Alexander, the women to whom the UCMP owes both its collection and existence.

Paleontologist J.P. Smith joined that expedition and published on the marine fauna in the early 1900s.

They formed the basis for his monograph on North American Middle Triassic marine invertebrate fauna published in 1914. N. J. Siberling from the US Geological Survey published on these outcrops in 1962. His work included nearly a dozen successive ammonite faunas, many of which were variants on previously described species.

Evidently, his collections consisted mainly of weathered material and were made without stratigraphic control because he believed that most, if not all, of these species, were coexistent. The fossiliferous beds found here, as well as localities in north-western Nevada, were designated the 'Daonella dubia' zone. Dubious would be closer to the truth. We've since mapped them out from stratigraphic sections to place them in the correct order of their occurrence.

Tuesday 22 October 2019

LATE HETTANGIAN TO EARLY SINEMURIAN FAUNA

Hiking the hills of Nevada looking for David Taylor's faunal succession based on ammonoids established for the Late Hettangian to Early Sinemurian interval in the Western Cordillera.

It was a tremendous experience to walk through time and compare the fossil assemblages here with our own in the Canadian Rockies.

Here the faunal sequence consists of one zone and four informal biochronologic units or assemblages and was outlined by Taylor as follows: Paracaloceras morganense assemblage, Badouxia oregonensis assemblage, Canadensis Zone, Metophioceras trigonatum assemblage and Coroniceras involutum. They matched up to specimens we collected over three field seasons to similar faunal outcrops of Late Hettangian to Early Sinemurian of the Last Creek and Tyaughton area of the Canadian Rockies.

The succession also correlates with the interval delineated by the Northwest European Angulata Zone through the Lyra Subzone. Two new genera (Guexiceras and Tipperoceras) are described along with 23 new species. The phylogenetic relationships of the earliest Jurassic ammonite superfamilies indicate that it is useful to include under the Psiloceratida, the Psilocerataceae and their derivatives including the Lytocerataceae. The Arietitaceae were derived from Hettangian lytocerataceans.

Wednesday 16 October 2019

MIDDLE TRIASSIC OF NEVADA

Searching for bedrock in outcrops of the West Humboldt Mountains, Nevada. Perhaps the most famous and important locality for the Middle Triassic (Anisian/Ladinian) of North America. These beautiful hills are home to Triassic ammonoid outcrops and plentiful ichthyosaur fossils.

J.P. Smith published on the marine fauna in the early 1900's. They formed the basis for his monograph on North American Middle Triassic marine invertebrate fauna published in 1914. N. J. Siberling from the US Geological Survey published on these outcrops in 1962. His work included nearly a dozen successive ammonite faunas, many of which were variants on previously described species.

Evidently, his collections consisted mainly of weathered material and were made without stratigraphic control because he believed that most, if not all, of these species were coexistent. The fossiliferous beds found here, as well as localities in north-western Nevada, were designated the 'Daonella dubia' zone. Dubious would be closer to the truth. Smith joined the 1905 Expedition of the University of California’s Department of Geology in Berkeley funded by the beautiful and bold, Annie Alexander, the women to whom the UCMP owes both its collection and existence.

Monday 30 September 2019

SHOSHONE MOUNTAIN RANGE

Berlin-Ichthyosaur State Park encompasses 1,540 acres. The elevation ranges from 6,840 feet to a high point of 7,880 feet. The hillsides in the park are covered with big sagebrush, while pinyon pine and Utah juniper dominate the upper elevations.

Common animal inhabitants include mule deer, black-tailed jackrabbits, cottontails, western bluebirds, pinyon jays, chukar partridge, whiptail lizards, western fence lizards, gophers and snakes.

​​Nestled at 7,000 feet on the western slope of central Nevada’s Shoshone mountain range, the park provides an array of stimulating recreational opportunities. The forested slopes provide shade, and breezes help to moderate the summer temperatures which seldom exceed 90˚F. Late spring and early fall can often be the nicest times of the year. Winter visits to the park are possible, but call for weather and road conditions before visiting.

Tuesday 30 April 2019

BLUE LIAS ICHTHYOSAUR

This well-preserved partial ichthyosaur was found in the Blue Lias shales by Lewis Winchester-Ellis in 2018. An exciting find to be sure. The vertebrae you see are from the tail section of this marine reptile.

The find includes stomach contents which tell us a little about how this particular fellow liked to dine.

As with most of his brethren, he enjoyed fish and cephalopods. Lewis found fishbone and squid tentacle hooklets in his belly. Oh yes, these ancient cephies had grasping hooklets on their tentacles. I'm picturing them wiggling all ominously. The hooklets were the only hard parts of the animal preserved in this case as the softer parts of this ancient calamari were fully or partially digested before this ichthyosaur met his end.

Ichthyosaurus was an extinct marine reptile first described from fossil fragments found in 1699 in Wales. Shortly thereafter, fossil vertebrae were published in 1708 from the Lower Jurassic and the first member of the order Ichthyosauria to be discovered.

To give that a bit of historical significance, this was the age of James Stuart, Jacobite hopeful to the British throne. While scientific journals of the day were publishing the first vertebrae ichthyosaur finds, he was avoiding the French fleet in the Firth of Forth off Scotland. This wasn’t Bonnie Prince Charlie, this was his Dad. Yes, that far back.

The first complete skeleton was discovered in the early 19th century by Mary Anning and her brother Joseph along the Dorset Jurassic Coast. Joseph had mistakenly, but quite reasonably, taken the find for an ancient crocodile. Mary excavated the specimen a year later and it was this and others that she found that would supply the research base others would soon publish on.

Mary's find was described by a British surgeon, Sir Everard Home, an elected Fellow of the Royal Society, in 1814. The specimen is now on display at the Natural History Museum in London bearing the name Temnodontosaurus platyodon, or “cutting-tooth lizard.”

In 1821, William Conybeare and Henry De La Beche, a friend of Mary's, published a paper describing three new species of unknown marine reptiles based on the Anning's finds.

The Rev. William Buckland would go on to describe two small ichthyosaurs from the Lias of Lyme Regis, Ichthyosaurus communis and Ichthyosaurus intermedius, in 1837.

Remarkable, you'll recall that he was a theologian, geologist, palaeontologist AND Dean of Westminster. It was Buckland who published the first full account of a dinosaur in 1824, coining the name, "Megalosaurus."

The Age of Dinosaurs and Era of the Mighty Marine Reptile had begun.

Ichthyosaurs have been collected in the Blue Lias near Lyme Regis and the Black Ven Marls. More recently, specimens have been collected from the higher succession near Seatown. Paddy Howe, Lyme Regis Museum geologist, found a rather nice Ichthyosaurus breviceps skull a few years back. A landslip in 2008 unveiled some ribs poking out of the Church cliffs and a bit of digging revealed the ninth fossil skull ever found of a breviceps, with teeth and paddles to boot.

Specimens have since been found in Europe in Belgium, England, Germany, Switzerland and in Indonesia. Many tremendously well-preserved specimens come from the limestone quarries in Holzmaden, southern Germany.

Ichthyosaurs ranged from quite small, just a foot or two, to well over twenty-six metres in length and resembled both modern fish and dolphins.

Dean Lomax and Sven Sachs, both active (and delightful) vertebrate paleontologists, have described a colossal beast, Shonisaurus sikanniensis from the Upper Triassic (Norian) Pardonet Formation of northeastern British Columbia, Canada, measuring 3-3.5 meters in length. The specimen is now on display in the Royal Tyrrell Museum of Palaeontology in Alberta, Canada. It was this discovery that tipped the balance in the vote, making it British Columbia's Official Fossil. Ichthyosaurs have been found at other sites in British Columbia, on Vancouver Island and the Queen Charlotte Islands (Haida Gwaii) but Shoni tipped the ballot.

The first specimens of Shonisaurus were found in the 1990s by Peter Langham at Doniford Bay on the Somerset coast of England.

Dr. Betsy Nicholls, Rolex Laureate Vertebrate Palaeontologist from the Royal Tyrrell Museum, excavated the type specimen of Shonisaurus sikanniensis over three field sessions in one of the most ambitious fossil excavations ever ventured. Her efforts from 1999 through 2001, both in the field and lobbying back at home, paid off. Betsy published on this new species in 2004, the culmination of her life’s work and her last paper as we lost her to cancer in autumn of that year.

Charmingly, Betsy had a mail correspondence with Roy Chapman Andrews, former director of the American Museum of Natural History, going back to the late 1950s as she explored her potential career in palaeontology. Do you recall the AMNH’s sexy paleo photos of expeditions to the Gobi Desert in southern Mongolia in China in the early 20th century? You’d remember if you’d seen them. Roy Chapman Andrews was the lead on that trip. His photos are what fueled the flames of my own interest in paleo.

We've found at least 37 specimens of Shonisaurus in Triassic outcrops of the Luning Formation in the Shoshone Mountains of Nevada, USA. The finds go back to the 1920s. The specimens that may it to publication were collected by M. Wheat and C. L. Camp in the 1950s.  The aptly named Shonisaurus popularis became the Nevada State Fossil in 1984. Our Shoni got around. Isolated remains have been found in a section of sandstone in Belluno, in the Eastern Dolomites, Veneto region of northeastern Italy. The specimens were published by Vecchia et al. in 2002.

For a time, Shonisaurus was the largest ichthyosaurus known.

Move over, Shoni, as a new marine reptile find competes with the Green Anaconda (Eunectes murinus) and the Blue Whale (Balaenoptera musculus) for size at a whopping twenty-six (26) metres.

The find is the prize of fossil collector turned co-author, Paul de la Salle, who (you guessed it) found it in the lower part of the intertidal area that outcrops strata from the latest Triassic Westbury Mudstone Formation of Lilstock on the Somerset coast. He contacted Dean Lomax and Judy Massare who became co-authors on the paper.

The find and conclusions from their paper put "dinosaur" bones from the historic Westbury Mudstone Formation of Aust Cliff, Gloucestershire, UK site into full reinterpretation.

And remember that ichthyosaur the good Reverend Buckland described back in 1837, the Ichthyosaurus communis? Dean Lomax was the first to describe a wee baby. A wee baby ichthyosaur! Awe. I know, right? He and paleontologist Nigel Larkin published this adorable first in the journal of Historical Biology in 2017.

They had teamed up previously on another first back in 2014 when they completed the reconstruction of an entire large marine reptile skull and mandible in 3-D, then graciously making it available to fellow researchers and the public. The skull and braincase in question were from an Early Jurassic, and relatively rare, Protoichthyosaurus prostaxalis. The specimen had been unearthed in Warwickshire back in the 1950's. Unlike most ichthyosaur finds of this age it was not compressed and allowed the team to look at a 3-D specimen through the lens of computerised tomography (CT) scanning.

Another superb 3-D ichthyosaur skull was found near Lyme Regis by fossil hunter-turned-entrepreneur-local David Sole and prepped by the late David Costain. I'm rather hoping it went into a museum collection as it would be wonderful to see the specimen studied, imaged, scanned and 3-D printed for all to share. Here's hoping.

Lomax and Sven Sachs also published on an embryo from one of the largest ichthyosaurs known, a new species named Ichthyosaurus somersetensis. Their paper in the ACTA Palaeontologica Polonica from 2017, describes the third embryo known for Ichthyosaurus and the first to be positively identified to species level. The specimen was the collected from the Lower Jurassic strata (lower Hettangian, Blue Lias Formation) of Doniford Bay, Somerset, UK and is housed in the collection of the Niedersächsisches Landesmuseum (Lower Saxony State Museum) in Hannover, Germany.

We've learned a lot about them in the time we've been studying them. We now have thousands of specimens, some whole, some as bits and pieces. Many specimens that have been collected are only just now being studied and the tools we are using to study them are getting better and better.

While they resembled fish and dolphins, Ichthyosaurs were large marine reptiles belonging to the order known as Ichthyosauria or Ichthyopterygia. In 2018, Benjamin Kear and his team were able to study ichthyosaur remains at the molecular level, Their findings suggest ichthyosaurs had skin and blubber quite similar to our modern dolphins.

While ichthyosaurs evolved from land-dwelling, lung-breathing reptiles, they returned to our ancient seas and evolved into the fish-shaped creatures we find in the fossil record today.

Their limbs fully transformed into flippers, sometimes containing a very large number of digits and phalanges. Their flippers tell us they were entirely aquatic as they were not well-designed for use on land. And it was their flippers that first gave us the clue that they gave birth to live young; a find later confirmed by fossil embryo and wee baby ichy finds.

They thrived during much of the Mesozoic era; based on fossil evidence, they first appeared around 250 million years ago (Ma) and at least one species survived until about 90 million years ago into the Late Cretaceous.

During the early Triassic period, ichthyosaurs evolved from a group of unidentified land reptiles that returned to the sea. They were particularly abundant in the later Triassic and early Jurassic periods before being replaced as premier aquatic predator by another marine reptilian group, the Plesiosauria, in the later Jurassic and Cretaceous periods.

In the Late Cretaceous, ichthyosaurs were hard hit by the Cenomanian-Turonian anoxic event. As the deepest benthos layers of the seas became anoxic, poisoned by hydrogen sulphide, deep water marine life died off. This caused a cascade that wreaked havoc all the way up the food chain. At the end of that chain were our mighty predaceous marine reptiles.

Bounty turned to scarcity and a race for survival began. The ichthyosaurs lost that race as the last lineage became extinct. It may have been their conservative evolution as a genus when faced with a need for adaptation to the world in which they found themselves and/or being outcompeted by early mosasaurs.

There are promising discoveries coming out of strata from the Cretaceous epeiric seas of Texas, USA from Nathan E. Van Vranken

His published paper from 2017, "An overview of ichthyosaurian remains from the Cretaceous of Texas, USA," looks at ichthyosaurian taxa from the mid-Cretaceous (Albian–Cenomanian) time interval in North America with an eye to ichthyosaurian distribution and demise.

The find and photos are all credited to Lewis Winchester-Ellis. Thank you for sharing your tremendous specimen with us. Lewis did much of the preparation of the specimen, removing the majority of the matrix. The spectacular final prep is credited to Lizzie Hingley, Stonebarrow Fossils, Oxfordshire. Her skill with an air scribe is unparalleled.

Link to Lomax Paper: https://journals.plos.org/plosone/article…

Link to Nathan's Paper: https://www.tandfonline.com/…/10.1080/03115518.2018.1523462…

Nicholls Paper: E. L. Nicholls and M. Manabe. 2004. Giant ichthyosaurs of the Triassic - a new species of Shonisaurus from the Pardonet Formation (Norian: Late Triassic) of British Columbia. Journal of Vertebrate Paleontology 24(4):838-849 [M. Carrano/H. Street]

Sunday 3 March 2019

ICHTHYOSAUR VERTEBRAE

Ichthyosaur vertebrae, Berlin-Ichthyosaur State Park
At least 37 incomplete fossil specimens of the marine reptile have been found in hard limestone deposits of the Luning Formation, in far northwestern Nye County of Nevada. This formation dates to the late Carnian age of the late Triassic period when present-day Nevada and parts of the west were covered by an ancient ocean.

The first researcher to recognize the Nevada fossil specimens as ichthyosaurs was Siemon W. Muller of Stanford University. He had the work of Sir Richard Owen to build on from the 1840s. That being said, there are very few contenders for a species that boasts vertebrae over a foot wide and weighing in at almost 10 kg or 21 lbs. Muller contacted the University of California Museum of Paleontology at Berkeley. Surface collecting by locals continued at the site but no major excavation was planned.

Almost a quarter of a century after Muller's initial correspondence to the UCMP, Dr. Charles L. Camp received correspondence further detailing the finds from a lovely Mrs. Margaret Wheat of Fallon. She wrote to Camp in September of 1928 to say that she'd been giving the quarry section a bit of a sweep, as you do, and had uncovered a nice aligned section of vertebrae with her broom. The following year, Dr. Charles L. Camp went out to survey the finds and began working on the specimens, his first field season of many, in 1954.

Back in the 1950s, these large marine reptiles were rumoured to be "marine monsters," as the concept of an ichthyosaur was not well understood by the local townsfolk. Excitement soon hit West Union Canyon as the quarry began to reveal the sheer size of these mighty beasts. In the end, the ichthyosaur bones were left in situ to better understand how they were laid down over 200 million years ago.

Camp continued to work with Wheat at the site and brought on Sam Welles to help with excavations. The team understood the need for protection at the site. They canvassed the Nevada Legislature to establish the Ichthyosaur Paleontological State Monument. You can one of the Park Rangers above giving a tour within the lovely building they built on the site to protect the fossils.

In 1957, the site was incorporated into the State Park System and Berlin-Ichthyosaur State Park was born. The park Twenty years later, in 1977, the population of Nevada weighed in and the Legislature designated Shonisaurus popularis as the State Fossil of Nevada.

Address: State route 844, Austin, NV 89310, United States. Area: 4.58 km². Open 24 hours;
Elevation: 6,975 ft (2,126 m); Tel: +1 775-964-2440; http://parks.nv.gov/parks/berlin-ichthyosaur