MOAI OF EASTER ISLAND

Carved Volcanic Moai Statues of Easter Island

Rapa Nui or Easter Island is a volcanic island and special territory of Chile in the southeastern Pacific. The island sits atop the Rano Kau Ridge and is built from the remains of three extinct volcanoes. Most of the rock here is hawaiite, an olivine basalt intermixed with iron-rich basalts, mafic extrusive igneous rocks formed from the rapid cooling of iron-rich lava near the islands core.

It is one of the most isolated inhabited islands now famous for its rows of carved moai statues. These quiet sentinels were carved by the islands' first inhabitants.

Sometime around 1200 AD, people from Polynesia began to settle on the island. It looked much different back then. There were lovely forests on the island and those first settlers build a thriving community and culture. A series of unfortunate events devastated the island and the population. Rats, deforestation, the slave trade and finally disease took their toll. But those early settlers are not forgotten. For one of the world's most isolated islands, it is still visited today to visit their greatest legacies — 887 towering carved figures, moai, made from the islands' volcanic rock. They quarried and carved the rock then moved their sculptures to a platform on the water's edge where they are visited and revered to this day.

PACHYDISCUS SUCHIAENSIS

Pachydiscus suchiaensis

The late Cretaceous ammonite Pachydiscus suchiaensis found in concretion amongst the 72 million-year-old grey shales of the Northumberland Formation, Campanian to the lower Maastrichtian, part of the upper Cretaceous, from Collishaw Point (Boulder Point to the locals), northwest side of Hornby Island, southwestern British Columbia.

Hornby is a glorious place to collect. The island is beautiful in its own right and the fossils from here often keep some of their original shell or nacre which makes them quite fetching.

This fellow is found amongst gastropods, shark teeth, fossil crabs, baculites and other bivalve fossils.

Like most of the fossils found at this locality, the specimen was found in concretions rolled smooth by time and tide. The concretions you find on the beach are generally round or oval in shape and are made up of hard, compacted sedimentary rock. If you are lucky, when you split them you see a fossil hidden within. The main topographic feature on Hornby Island is an arcuate mountain consisting of the resistant cliff-forming Geoffrey formation.

Near Shingle Spit about half a mile from the coast is Mount. Geoffrey 920-foot peak; from there the mountain gradually drops in elevation to the southeast and to the north.  It consists of a structurally simple 700-foot conglomerate homocline striking N 20° W and dipping to the northeast at a shallow angle of about 6°. The apex of the arcuate mountain belt points to the southwest.

Behind the mountain and almost enclosed by it is the fertile, green Strachan Valley. On the large peninsula which extends in a southeast direction from the north of the island towards St. John’s Point, the Hornby Formation outcrops forming the cliffs on the east side of Tribune Bay. The highest of these is about 200 feet. The argillaceous Lambert and Spray formations form the subdued lowlands of the island.

The coast of Hornby is probably a rising shoreline, as indicated by the almost perpendicular cliffs along its periphery. A hundred (100) foot cliffs of Lambert shale extends from Shingle Spit to Phipps Point, while from the latter to Boulder Point, the cliffs are not as steep and are covered in many places by vegetation.

ALBERTONECTES OF THE WESTERN INTERIOR SEAWAY

Albertonectes vanderveldei

During the Cretaceous, the Western Interior Seaway split North America into two landmasses. Part of the seaway was the Bearpaw Sea, a warm, shallow body of water that covered 1.7 million square kilometres of the coastal plain about 74 million years ago.

The Bearpaw Formation is a geologic formation of Late Cretaceous (Campanian) age. It outcrops in the U.S. state of Montana, as well as the Canadian provinces of Alberta and Saskatchewan, and was named for the Bear Paw Mountains in Montana. It includes a wide range of marine fossils, as well as the remains of a few dinosaurs. It is known for its fossil ammonites, some of which are mined in Alberta to produce the organic gemstone ammolite.

It was home to many marine reptiles, ammonites, fish, and other aquatic life. Elasmosaurs —long-necked plesiosaurs — were one group of marine reptiles that inhabited these ancient waters.

They were primarily fish eaters, and used their long necks to strike at fish, then trapped them in their interlocking teeth. A new genus and species of elasmosaur, Albertonectes vanderveldei, was uncovered in 2007 during ammonite shell mining.

Albertonectes has 76 neck vertebrae, the most of any animal known — compare this to giraffes that only have seven neck vertebrae. Albertonectes had a neck that was 6.5 metres long. Was it flexible and able to bend sharply and quickly? Or was it stiff, with a gentle arc that could cover a large area? Palaeontologists used computer modelling to study the neck’s flexibility. The neck broke into four segments when it collapsed on the seafloor.

This incredible specimen provides insight into what marine communities were like during the Cretaceous Period. The fossilized remains of other animals that lived alongside Albertonectes are found in the rocks formed at the bottom of the Bearpaw Sea. These included potential prey such as small fishes, ammonites, and crayfish. From recovered shark teeth, and tooth marks left on the bone, palaeontologists determined that the carcass of Albertonectes. was scavenged by one or more sharks.

More on this impressive find:
https://royaltyrrellmuseum.wpcomstaging.com/./albertonecte…/

Photo: Roland Tanglao from Vancouver, Canada - 5d-dinosaur-camp-day2-20120802-64.jpgUploaded by FunkMonk, CC BY 2.0, https://commons.wikimedia.org/w/index.php?curid=20902049

DESMATOCHELYS FROM THE PUNTLEDGE

A lovely fossil turtle, Desmatochelys cf. D. lowi (Williston, 1894) found by Richard Bolt in the shales of the Trent River Formation along the Puntledge River in the early 1990s. At the time, it was the first documented account of a Cretaceous marine vertebrate from the Pacific coast of Canada — a first which shows you how much we've learned about our Pacific coast in just the last few years.

Dr. Betsy Nicholls wrote up the paper and published in the Canadian Journal of Earth Sciences in 1992. She described the specimen from some post cranial elements and part of the mandible. Unfortunately, we were never able to recover the skull.

It was the Desmatchelys that inspired the 1999 BCPA Symposium conference logo held at UBC that year — a trilobite embedded within a turtle, celebrating recent significant contributions to Canadian palaeontology. It was also the inspiration for the sculpture you see here by Peter Odendag. I met Peter at the conference and was delighted to see his paleo inspired sculptures. Both his Desmatochelys and coelacanth now grace the displays at the Courtenay Museum on Vancouver Island.

While this was the first turtle find on Vancouver Island, the hunt for our fossilized reptilian friends goes back many years, but the hunt for Desmatochelys begins in the Bone Wars of the late 1800s. It was Samuel Wendell Williston who described the first specimen of Desmatochelys in the Kansas University Quarterly in 1895. Williston was a contemporary of C.H. Sternberg, Edward Drinker Cope and Othniel Charles Marsh. As history tells it, from 1877 to around 1892, both Cope and Marsh used their wealth and influence to finance their own expeditions and to procure the services and dinosaur bones from lesser fossil hunters. Williston was one of Marsh's boys.

Desmatochelys cf. D. lowi, Upper Cretaceous Haslam Formation 

In 1876, Williston wrote a letter to Marsh reporting that Sternberg had, "got one or two large turtles that are good and some pretty good saurians," (Shor, 1971:77) along the Smoky Hill River, upper Chalk Logan County.

Williston's hunt for turtles continued and it was not long after that he would hold in his hand a new species on which he would both publish and name. The specimen had been found by a railroad worker near Fairbury, Nebraska. These were hard times and fossils were exchanged for hard currency then as they are today. The specimen was passed through the hands of one curiosity seeker after another until it eventually made its way to M. A. Low. The good Master Low was more a man of science than currency and he generously donated to the University of Kansas in 1893.

That generosity was rewarded. Had the specimen not be accessioned into the collections at Kansas University by Low, it might well have been sold to Marsh and published under the name Marshanii. Instead, Williston was given the fossil to study. He published and in discovering it was a new species, chose the scientific name for the specimen. Williston tipped his hat to Low and called the new species Desmatochelys Iowi when published his finding on a well-preserved fossil turtle (KUVP 1200) from the Upper Cretaceous Benton Formation of Fairbury, Nebraska, later that year. The find included the skull, lower jaw and portions of the carapace, plastron, limbs and limb girdles. Williston described it as a new genus and species of marine turtle, Desmatochelys Iowi, and placed it in a new family, Desmatochelyidae. Since its first discovery at least five new specimens of D. lowi have been described from Cretaceous deposits in South Dakota, Kansas, Arizona, Canada, and Mexico.

In 1960, the carapace, limbs and limb girdles of a second specimen (CNHM PR 385) were found in Cretaceous sediment deposits with pre-Cambrian granites in a quarry on the South Dakota-western Minnesota border (Zangerl and Sloan, 1960). They pushed back on Williston's assertion that his new species belonged in the newly described family Desmatochelyidae, instead of recognizing it to be a primitive cheloniid within the family Cheloniidae — a family of large marine turtles characterized by their flat "hard-shells" with their streamlined, wide, rounded shapes and paddle-like forelimb flippers.

References for further reading:

• Calloway, Jack; Nicholls, Elizabeth, eds. (1997). Ancient Marine Reptiles. Academic Press. p. 243. ISBN 9780080527215.
• Raselli, I. 2018. Comparative cranial morphology of the Late Cretaceous protostegid sea turtle Desmatochelys lowii. PeerJ 6:e5964 https://doi.org/10.7717/peerj.5964