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   Volume 81 - Issue 23 Website:www.passherald.ca   email: news@passherald.ca   $1.00   
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Story
John Kinnear photos
The original discovery site - trackways in all directions
Rich McCrea standing below the trackway latex cast.
Looking Back - John KinnearThe fossil record has always fascinated me as it contains a remarkable history of what was around way before we showed up on this planet. One of my favourite prehistoric topics is dinosaur footprints, rare physical evidence that something long extinct walked by somewhere. Finding them is extremely uncommon and every child’s eyes light up when you tell them that they are looking at the footprint evidence of something exotic like an allosaurus or a velociraptor.
Coal mines occasionally expose a print here and there but given that blasting rock to access coal seams is part of the mining process, finding one is extremely exceptional. It usually happens when we mine past the blasted rock to an undisturbed plane and expose a thin veneer that contains trackways. They may not always be obvious and there is a trick to looking for them. The idea is to have the sun hit that plane or surface at an angle to create a shadow in the often very slight depression that has been left behind. That gives them a bit of definition.
In thirty years of studying the rocks in the Line Creek valley there has only been a half dozen times that these magical discoveries have happened for me and the thrill is always the same.
The most recent discovery was back in 2008 when an exploration road contractor came up to me and asked if we had seen the dinosaur footprints on a ridge north of the mine. I scoffed at what I thought was an amateur’s guess at some curious bit of geology but boy was I wrong. A subsequent investigation revealed a tantalizing series of rough ovals in a shale bed that had been exposed and carefully sloped by a backhoe.
A report of this interesting find along with some pictures found its way to a palaeontologist by the name of Richard McCrea from the Peace River Palaeontological Research Center in Tumbler Ridge, BC. Rich and assistant Tyler Shaw liked what they saw and quickly organized a two week expedition to the site to see first-hand what had been uncovered. Rich McCrea had been out our way looking for trackways before but this one was for him the jackpot. He determined that the series of tracks were from very large dinosaurs knows as sauropods also called informally “brontosaurs”. This was pretty exciting stuff as up until then Canada had not a single record of saurapod dinosaurs either from footprints or bones. It was somewhat of a mystery why and palaeontologists were at a loss to explain.
McCrea had presented a paper at an international symposium in Arizona in 2005 detailing his discovery of this major group of dinosaurs based on isolated footprint blocks found in mine dumps in the Elk Valley. Now it appeared he had the full blown evidence of their presence with this trackway discovery.
Trackways give much more information than single footprints, such as a better feel for the size of the track-maker, his habitat, how fast he was travelling or whether he was alone or in a herd.
It was a fellow by the name of Robert McNeill Alexander, a British zoologist, who recognized that all animals move as scale models of one another.
 
Cats, dogs, camels, horses, all look the same at the same speed. He devised a formula using the leg length of animals and their stride length which he got from their tracks. He then applied this formula to dinosaurs by measuring the fossil leg bones and their stride length which he got from fossil trackways. He was then able to calculate the speed at which “dino” was moving when he scampered, meandered, roamed, galloped or drifted by.
Story 1
John Kinnear photos
The four tracks chosen to be preserved.
The ancient ripples of a seashore.
Size 13 - ‘Destined to disappear’.
There are no less than 14 different measurements of a trackway you can take such as stride and pace length, width and length of foot, digit divarification etc. From this, one can determine if the beast was bipedal or quadrapedal, squatty like a turtle or sinuous like a lizard, slow like an alligator or fast like a velociraptor. Remember him, that hell on wheels fellow from Jurassic Park? A jogger’s worst nightmare.
Rich and his assistant set about measuring and evaluating the prints and decided that the vulnerable shale bed would never last two years. So a series of coats of sweet latex were applied to four of the prints to create a replica peel of the most prominent trackway. The 45 gallons of latex peel weighed between 200-250 kilograms and measured almost 10 meters by 3 meters. Fortunately it could be rolled up for a very careful trip back to Tumbler Ridge. The peel will be used to create high-fidelity casts for permanent research and display at the PRPRC, whose goal is to become the central repository and display center for British Columbia vertebrate fossils as well as an international center for palaeontological research and education.
What an amazing story this is! If you contemplate all the footprints that man and animals lay down in a single day and how many of them survive it gives you an idea just how rare it is to find dinosaur trackways. A few years ago I left my size 13 footprint on a beach in Parksville, BC and as I studied it and the ripples left in the sand next to it, the picture of an ancient prehistoric seashore came to mind. A few months after that I noticed that a 135 million year old seashore from the Mist Mountain formation that straddles the Jurassic-Cretaceous boundary had been exposed at the mine with not a hint of a trackway on it. I wasn’t at all surprised!
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   Volume 81 - Issue 23 Website:www.passherald.ca   email: news@passherald.ca   $1.00   
 
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