Wednesday, 23 March 2016
DRAGONFLIES: ANCIENT PREDATORS
Dragonflies, from the order Odonata, have been around for
over 250 million years. The most conspicuous difference in their evolution over
time is the steady shrinking of their wingspan from well over two and a half
feet down to a few inches.
Voracious predators, today they dine on bees, wasps,
butterflies and avoid the attentions of birds and wee lizards -- but back in the day, they had a much larger
selection of meals within their grasp. Time has turned the tables. Small lizards and birds who
today choose dragonflies as a tasty snack used to be their preferred prey.
Monday, 21 March 2016
Wednesday, 16 March 2016
Sunday, 13 March 2016
PALTECHIOCERAS OF WRANGELLIA
Those working in the Jurassic exposures on Vancouver Island are a determined crew. Most of the sedimentary deposits of the Jurassic are exposed in the hard to reach areas between Nootka Sound and Cape Scott.
By the time these ammonites were being buried in sediment, Wrangellia, the predominately volcanic terrane that now forms Vancouver Island and the Queen Charlotte Islands, had made its way to the northern mid-laditudes.
This detail of the Jurassic ammonite, Paltechioceras sp. shot with an ultra-low f-stop, is from an all but inaccessible site in Sayward, Bonanza Group, Vancouver Island.
We did a fossil field trip up there a few years ago with the Courtenay & Qualicum beach crew. The drive up the mountain was thrilling as the road narrowed until it was barely the width of our wheel base. Thrilling to say the least.
By the time these ammonites were being buried in sediment, Wrangellia, the predominately volcanic terrane that now forms Vancouver Island and the Queen Charlotte Islands, had made its way to the northern mid-laditudes.
This detail of the Jurassic ammonite, Paltechioceras sp. shot with an ultra-low f-stop, is from an all but inaccessible site in Sayward, Bonanza Group, Vancouver Island.
We did a fossil field trip up there a few years ago with the Courtenay & Qualicum beach crew. The drive up the mountain was thrilling as the road narrowed until it was barely the width of our wheel base. Thrilling to say the least.
Friday, 19 February 2016
Tuesday, 16 February 2016
Tuesday, 2 February 2016
Saturday, 23 January 2016
LINCOLN CREEK FORMATION: EOCENE-OLIGOCENE BORDER
Fossil crabs, several dozen species of mulluscs including the elusive tusk shell have been found in the fossil exposures of the Lincoln Creek Formation, southern Olympic Peninsula, near the town of Porter, Washington, 46°56'20"N, 123°18'38"W.
It is a site I return to each year to see the erosion and what new specimens have worked their way to the surface.
The whitish strata consists of tuffaceous siltstone and sandstone with concretionary beds throughout. They are slightly older than originally thought, coming in around 37 million-years, straddling the Eocene-Oligocene border. Here a lovely crab, Pulalius vulgaris, sits in the sand. He would be in good company at the site amongst the more common scaphodpod shells and other wee gastropods.
The whitish aragonitic shells of scaphopods are conical and curved with a planispiral curve, looking a bit like an elephant's tusk, hence their common name. They prefer to live on soft substrates in subtidal zones so they are not as abundant or readily visible on our beaches as their gastropods and bivalves compatriots. Tusk shells and their fossil relatives, however, are found commonly in the sediments at Porter and other localities throughout the Pacific Northwest while crabs are found, but more rare.
It is a site I return to each year to see the erosion and what new specimens have worked their way to the surface.
The whitish strata consists of tuffaceous siltstone and sandstone with concretionary beds throughout. They are slightly older than originally thought, coming in around 37 million-years, straddling the Eocene-Oligocene border. Here a lovely crab, Pulalius vulgaris, sits in the sand. He would be in good company at the site amongst the more common scaphodpod shells and other wee gastropods.
The whitish aragonitic shells of scaphopods are conical and curved with a planispiral curve, looking a bit like an elephant's tusk, hence their common name. They prefer to live on soft substrates in subtidal zones so they are not as abundant or readily visible on our beaches as their gastropods and bivalves compatriots. Tusk shells and their fossil relatives, however, are found commonly in the sediments at Porter and other localities throughout the Pacific Northwest while crabs are found, but more rare.
Thursday, 31 December 2015
TUSKS AND BONE: TANGIERS
During the Miocene and Pliocene, 12-1.6 million years ago, a diverse group of extinct proboscideans, elephant-like animals walked the Earth.
Most of these large beasts had four tusks and likely a trunk similar to modern elephants. They were creatures of legend, inspiring myths and stories of fanciful creatures to the first humans to encounter them.
Beyond our neanderthal friends, one such fellow was Quintus Sertorius, a Roman statesman come general, who grew up in Umbria. Born into a world at war just two years before the Romans sacked Corinth to bring Greece under Roman rule, Quintus lived much of his life as a military man far from his native Norcia. Around 81 BC, he travelled to Morocco, the land of opium, massive trilobites and the birthplace of Antaeus, the legendary North African ogre who was killed by the Greek hero Heracles.
The locals tell a tale that Quintus requested proof of Antaeus, hard evidence he could bring back to Rome to support their tales so they took him to a mound at Tingis, Morocco, where they unearthed the bones of a Neogene elephant, Tetralophodon.
Tetralophodon bones are large and skeletons singularly impressive. Impressive enough to be taken for something else entirely. By all accounts these proboscidean remains were that of the mythical ogre Antaeus and were thus reported back to Rome as such. It was hundreds of years later before their true heritage was known.
Monday, 21 December 2015
Saturday, 19 December 2015
Friday, 20 November 2015
Tuesday, 10 November 2015
Wednesday, 4 November 2015
Thursday, 15 October 2015
TYLOSTOME TUMIDUM
This lovely big fellow is Tylostoma tumidum, an epifaunal grazing Lower Cretaceous Gastropod from the Goodland Formation near Fort Worth, Texas, USA. (171.6 to 58.7 Ma)
Thursday, 8 October 2015
PALM TRUNK MOULD
George Mustoe of the Burke Museum preparing to make a mould of a palm trunk that once gew in the wetlands that bordered an ancient river.
Sunday, 20 September 2015
ERBENOCHILE ERBENI
A spectacular specimen of the trilobite Erbenochile erbeni. This impressive fossil arthropod shows unusual schizochroal eyes characteristic of the genus.
Family Odontopleuridae, Odontopleurid trilobite from the Lower Devonian, Emsian, 408 to 393 MYA, Bou Tiskaouine Formation, Hamar l”Aghdad Limestones, Taharajat, Oufaten, Djebel Issoumour
Family Odontopleuridae, Odontopleurid trilobite from the Lower Devonian, Emsian, 408 to 393 MYA, Bou Tiskaouine Formation, Hamar l”Aghdad Limestones, Taharajat, Oufaten, Djebel Issoumour
Saturday, 22 August 2015
Sunday, 2 August 2015
Sunday, 26 July 2015
Wednesday, 22 July 2015
Thursday, 16 July 2015
ICHTHYOSAUR EVOLUTION
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.
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.
Tuesday, 14 July 2015
Monday, 29 June 2015
GULLS ON THE FORESHORE: T'SIK'WI
A gull cries in protest at not getting his share of a meal |
Gulls, or colloquially seagulls, are seabirds of the family Laridae in the suborder Lari.
The Laridae are known from not-yet-published fossil evidence from the Early Oligocene — 30–33 million years ago.
Three gull-like species were described by Alphonse Milne-Edwards from the early Miocene of Saint-Gérand-le-Puy, France.
Another fossil gull from the Middle to Late Miocene of Cherry County, Nebraska, USA, has been placed in the prehistoric genus Gaviota.
These fossil gulls, along with undescribed Early Oligocene fossils are all tentatively assigned to the modern genus Larus. Among those of them that have been confirmed as gulls, Milne-Edwards' "Larus" elegans and "L." totanoides from the Late Oligocene/Early Miocene of southeast France have since been separated in Laricola.
Gulls are most closely related to the terns in the family Sternidae and only distantly related to auks, skimmers and distantly to waders.
A historical name for gulls is mews, which is cognate with the German möwe, Danish måge, Swedish mås, Dutch meeuw, Norwegian måke/måse and French mouette. We still see mews blended into the lexicon of some regional dialects.
In the Kwak̓wala language of the Kwakwaka'wakw, speakers of Kwak'wala, of the Pacific Northwest and my family, gulls are known as t̕sik̕wi. Most folk refer to gulls from any number of species as seagulls. This name is a local custom and does not exist in the scientific literature for their official naming. Even so, it is highly probable that it was the name you learned for them growing up.
If you have been to a coastal area nearly everywhere on the planet, you have likely encountered gulls. They are the elegantly plumed but rather noisy bunch on any beach. You will recognize them both by their size and colouring.
Gulls are typically medium to large birds, usually grey or white, often with black markings on the head or wings. They typically have harsh shrill cries and long, yellow, curved bills. Their webbed feet are perfect for navigating the uneven landscape of the foreshore when they take most of their meals.
Most gulls are ground-nesting carnivores that take live food or scavenge opportunistically, particularly the Larus species. Live food often includes crab, clams (which they pick up, fly high and drop to crack open), fish and small birds. Gulls have unhinging jaws which allow them to consume large prey which they do with gusto.
Their preference is to generally live along the bountiful coastal regions where they can find food with relative ease. Some prefer to live more inland and all rarely venture far out to sea, except for the kittiwakes.
The larger species take up to four years to attain full adult plumage, but two years is typical for small gulls. Large white-headed gulls are typically long-lived birds, with a maximum age of 49 years recorded for the herring gull.
Gulls nest in large, densely packed, noisy colonies. They lay two or three speckled eggs in nests composed of vegetation. The young are precocial, born with dark mottled down and mobile upon hatching. Gulls are resourceful, inquisitive, and intelligent, the larger species in particular, demonstrating complex methods of communication and a highly developed social structure. Many gull colonies display mobbing behaviour, attacking and harassing predators and other intruders.
Certain species have exhibited tool-use behaviour, such as the herring gull, using pieces of bread as bait with which to catch goldfish. Many species of gulls have learned to coexist successfully with humans and have thrived in human habitats. Others rely on kleptoparasitism to get their food. Gulls have been observed preying on live whales, landing on the whale as it surfaces to peck out pieces of flesh. They are keen, clever and always hungry.
Wednesday, 3 June 2015
Monday, 25 May 2015
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