Miscellany

Contents Updated: Tuesday, August 24, 1999

• Earliest Cloth
• Planet Death
• Algal Blooms
• Climate Changes
• Biodiversity
• All The Dinosaurs That Lived
• Cotswold Dinosaurs
• Dinosaur Metabolism
• Dinosaur Eggs
• Dinosaur Parenting
• Cretaceous Arctic Temperatures
• What Is Science, Anyway?
• Carnivorous Plants

Earliest Cloth

A piece of cloth wrapped around a piece of antler has been dated at 10,000 BP. Found in Cayonu, south east Turkey, by the head waters of the river Tigris, the only reason the fabric was preserved was because it had become impregnated with calcium salts. The site from about 7,500 BC was early Neolithic and skins rather than textiles were expected as the norm. Stone age men were more advanced than had been thought.

Ab electron microscope at UMIST showed that the fibre seemed to be flax, hemp or nettle. Flax seeds have been found at the site so the cloth is probably linen. The antler bone to which it was attached was probably the handle of a sickle, so the fabric must have been meant to improve the harvester’s grip. It was probably a piece of discarded clothing turned to other use. Previously the oldest cloth sample had dated from 6,500 BC and came from Israel but the impression of a fabric from 500 years earlier than the Turkish specimen is known from not far away in north east Iraq.

Planet Death

The human species is an environmental abnormality.

E O Wilson

Humanity is suicidal. Since the War public measures of welfare show that we have mostly enjoyed and improvement in material wealth. Yet, disillusionment is high. People are not happier. They are anxious and frustrated. They feel cheated. Material prosperity has not led to universal happiness.

The logic of science has brought us material progress but it has pooh-poohed our intuitive sense that all is not right. We are not the masters of all we survey. We are part of the world that we survey—but seem to have forgotten that we are!

We are genetically programmed to be selfish. We consider ourselves first then our families and then tribe or nation. Any sense of global responsibility is too weak or non-existent. Nor do we plan ahead for more than the generations which we see about us before we die—one or two at the most, remembering that few people would have seen beyond their sons and daughters or perhaps grandchildren in the time of mankind’s evolution. So in evolutionary terms there was no need, in an apparently infinite world, for any evolving human to consider more than its immediate family in distance and time.

Perhaps a law of evolution is that intelligence extinguishes itself. When a mass extinction occurs, it takes about 10 million years for the biodiversity to be restored to its former level. We have a poor grasp of the way that species interact to support each other. Each species down to fungi and bacteria has its niche with particular conditions. If those conditions change, it is hard to say what the knock on effect of the loss of that habitat will be on other species dependant upon it. Symbiosis is the rule of nature. When species are joined in symbiosis, the loss of one means the loss of the other. All species are interconnected, so the loss of any could be important to another far removed. All depend upon certain arrangements and hierarchies. We ride roughshod over these at our peril.

One laissez-faire school of thought ignores this, claiming that God has given us human ingenuity so that we can transcend the common rules of ecology. Ingenuity and the power of our technology can find solutions to problems. Would that it were so. The ecological systems are too complicated and once they have been destroyed, they cannot be studied. Even if they had, it is unlikely that we would know how to replace them.

Amphibian species in many parts of the world are declining sharply. In much of the Americas from the Canadian Rockies through the US Rockies,to Costa Rica, the Amazon basin and the Andes, not to mention places as far apart as Italy and Australia, amphibians are suffering or dying out. Not all regions have been surveyed so it is probably safest to assume that the phenomenon is global or essentially global. Causes might be desiccation from the global heating, fragmentation of habitats, UV damage through ozone layer destruction and pollution.

The thin skin of amphibians leaves them particularly susceptible to pollutants. Their habitats often collect pollution run off and they suffer accordingly. Since they are predators of pests such as flies, they could lead to serious environmental problems if they declined significantly.

A second problem is the mass deaths of dolphins and seals, often apparently from bacterial infections. It happened off the eastern US coast in 1987-88, when half the doplphins died, and as far away as in Lake Baikal in Russia at the same time when a tenth of the seals there died. 40% of seals in the Baltic and North Seas also died of viral infections triggered by pollution damage. Whole coral reefs and their inhabitants like sea urchins are also dying.

Many species of fish have been found to suffer from tumours particularly in the Great Lakes and particularly associated with the liver—a sign of pollution. Half of marine turtles in the Pacific and Caribbean have tumours.

Lastly certain migrating birds have declined by up to 50 per cent since the 1950s. Many bird populations are declining through pollution and loss of habitat, especially in the tropics.

Even amateur naturalists can use some of these sensitive species for monitoring. They can estimate amphibian populations and the populations of dragon flies, damsel flies and tiger beetles. Mosses and lichens can be monitored even more easily and have slow growing populations at the best of times, so that a noticeable decline would be likely to have significance.

What is the cause, though? Most likely is the 50,000 synthetic chemicals which are deposited into our environment with attempt to know their consequences.

Algal Blooms

Another problem has been the increase in poisonous coastal algal blooms. They have occurred from Japan, Hong Kong and Thailand to the Black and Baltic seas, the Adriatic and the eastern US seaboard. They seem to be caused by excessive leachates of nutrients like phosphates and nitrates combined with certain toxic chemicals.

Microscopic algae are the grass of the sea. They are present in the plankton in vast numbers but their concentration is normally low and a microscope is needed to see them. Sometimes however they bloom into vast numbers per millilitre and the water goes opaque with their bodies. The water looks like dishwater and the feeders on algae might have a lush pasture to feed on. In some cases it is less pleasant, and for us living near a body of water it might be too.

Algae are plants and produce oxygen by photosynthesis during the day. But at night they use up oxygen in the water to breathe and can suffocate animals swimming in their midst. The blooms of algae can also block the gills of fish, a problem of fish farming. The farmers have to be on the lookout for algal blooms and replenish the water as fast as they can to prevent suffocation. If they are too late, millions of pounds worth of fish can die.

Some algae have developed poisons to inhibit grazers from devouring them. Of course, fish might have little choice if they swim into a patch of algae and take some into their bodies. It is when the fisherman eats them that the poisonous nature of the algae is realised. When he landed there in 1793 the natives of British Colombia told George Vancouver that they never ate shellfish when the tide glowed at night. The reason was that the phosphorescence was caused by a poisonous alga. Such algae have killed hump-backed whales and manatees. The alkaloid poison they contain is so poisonous that a minute amount is toxic to people.

About 2000 cases of human poisoning by algae are reported each year—about one in six die. The first symptom will be numbness about the mouth and lips. The numbness will spread and in severe cases will paralyse the muscles for swallowing then breathing and the victim dies. Other types cause diarrhoea and sickness but are usually not fatal and another variety causes persistent nerve damage causing unsteadiness. When toxic algae are reported, the economic consequences on fish or shellfish exporting regions can be devastating. No one wants to import potentially poisonous fish.

Most of the toxic algae are localised and the natives have learnt when and what to eat. But widespread shipping in which water is used as ballast has transported strange blooms to unusual parts of the world. Algal poisoning from shellfish was unknown in Australia until the 80s when it began to occur around the ports of Adelaide, Hobart and Melbourne. It was traced to ships from Japan.

Human pollution is causing the main problem—providing excess nutrients that produce algal blooms. Waste from paper mills in the Seto area of Japan where many fish were farmed caused an algal bloom in 1972 that killed 14 million fish valued at $500 million.

It is total folly to neglect the rest of life. Our only hope is to try to halt the headlong plunge into death that we are currently following. Population growth has to be halted or it will halt itself. Exploitation of the earth’s resources has to halt or they will run out or degrade to a state of uselessness. Pollution has to be halted almost absolutely.

Meanwhile whatever portions of the earth and its species can be conserved until we understand it fully must be conserved.

Climate Changes

Cores from the Greenland icecap show that during the last ice age 20,000 years ago the north Atlantic warmed quickly by several degrees for hundreds of years before reverting, again quickly, to it cool state in an oscillation of several short lived cycles. It is conjectured that the build up and collapse of ice sheets over eastern Canada caused these. The theory is confirmed by drillings from the sea bed which show waves of icebergs periodically spreading over the Atlantic. The build up of the ice sheet cools the air over the Atlantic by the cold winds blowing off it and these cause the water to cool quickly. When the sheet collapses the ocean temporarily warms up.

The idea is that the ice sheets grow until the mass of ice insulates the heat emitted by the earth beneath it causing it to melt at its base. The sheet is then floating and slides quite quickly (over a period of years) into the sea. There it breaks up into lots of icebergs.

After the earth began to warm again about 12,900 years ago it relapsed into ice until 11,600 in a period called the Younger Dryas, named after the spread of a characteristic flower. The idea behind this is that the heating melted the icecaps causing the Atlantic to be covered with cold fresh water that suppressed convection in the ocean. The reason is that the cold water was less dense than the cold salt water blow it and therefore had no tendency to sink and mix. The cold surface water would have chilled the land until it had gradually mixed in with the underlying brine and recreated normal mixing conditions whereby the cold brackish water is dense enough to sink and ultimately push up cold water to the surface further south where it warms and cycles towards the north. The release of the cold fresh water bind will have been quite strong with a thousand years of heating behind it. The warmer northern oceans led to much higher snowfalls over the land. The build up of snow at the heart of the Greenland ice cap doubled in three years. The same is happening now, albeit more slowly, because of global warming. The snow melts at the fringes of the ice cap but deposits in its centre.

Regrettably, this picture should be confirmed by studies of the growth of coral. Coral has to grow just beneath the surface of the sea to get enough sunlight. When the ocean level rises, the coral has to grow upwards at the same rate as the rise. Cores drilled from reefs in the Barbados islands do not confirm the deductions from the ice cap cores. The point is that the rise should have slowed down or stopped when the cold snap of the Younger Dryas cut in. Actually, the coral cores show that melting of the ice slowed earlier. However, more recent studies on reefs in Papua confirm the theory so it seems there is some fault in the data from Barbados. This remains to be explained but the theory is looking sounder.

Biodiversity

No one knows how many species there are. Yet, species are disappearing at a rate between 30 and 100 thousand a year.

About 1.5 million have been classified but there could be 10 million yet to find or, less likely, as many as 100 million. Estimates of the number of insect species go as high as 30 million but 10 million is a more likely upper limit. Some 70,000 fungi have been classified. There could be 1.5 million. Only 14,000 bacteria are known out of a possible 300,000. We know of only 12,000 nematodes out of possibly millions—80 to 90 per cent of the worlds animals—and 30,000 mites out of a possible million. An acre of English pasture has 70 million beetles, 250 million springtails and nearly 700 million mites.

The floor of the oceans is almost unknown and for long considered almost sterile supporting only 160,000 species all together. Now scientists think there could be 10 million species down there, nearly all unclassified.

In 1976 two large animals were discovered in the sea, the megamouth shark, a new family let alone species, and the mesosplodon, the smallest whale. Cuban taxonomists identified three new geckos, four snakes, five frogs and seven lizards in just a couple of years at the start of the decade. About 100 new species of fish are found every year. 43 new species of bird were found in the 80s—discoveries continue. Even new primates are being found, lemurs and marmosets, among others.

It is guessed that human beings weigh the same as all of the insect species—they have the same biomass. Six billion humans need to keep 3 billion sheep, pigs and so on, 9 billion and 1.5 billion cows.

All The Dinosaurs That Lived

Perhaps 50,000 dinosaur genera and up to half a million individual species populated the Mesozoic from the Middle Triassic until the end of the Cretaceous, about 160 million years. As many as 90% of these taxa lived where their remains were not preserved as fossils and we shall therefore never know anything about them. Many of these taxa were small, crow-sized, birdlike forms seldom found fossilized even in regions favorable to fossilization because they were so small and fragile. Several thousand dinosaur genera might have been alive at any one time in the Mesozoic but only about a hundred or two of the big dinosaurs, entirely in line with ratios for extant mammals, birds, and reptiles.

Cotswold Dinosaurs

The remains of a forest pool were found in the 80s in the Cotswolds, a picturesque region of England based on a range of low hills. Some 165 million years ago the pool teamed with life, the excavations yielding up 30,000 fossils, including parts of four dinosaurs, one of which was a stegosaur. It was only small being about 15 feet wide and a few feet deep but it was surrounded by a forest of conifers, cycads and horsetails.

The most remarkable finds were tiny teeth of an unknown bird-like dinosaur about as big as a pheasant. It is considered not to have been a bird because it pre-dated Archaeopteryx, though the finds in China might have changed that view. Few people today deny that the evidence increasingly points to birds being a type of dinosaur or descended from them. They had the same hollow bones, a similar stance, laid eggs and looked after their young. Remains were also found of mammals—in those days tiny rodent-like animals that had their time cut out trying to avoid being eaten by the smaller predatory dinosaurs. There were also lots of frogs and salamanders and some fish. Trying to get them was a variety of crocodiles. Remains were also found of pterosaurs and insects. It seems that the habitat was as diverse in species as a similar place today. Plainly, the pool served as a watering hole and either sick animals fell in and died there or they were ambushed by predators. Today, we can see that prey species can be quite relaxed in the presence of a predator when they sense that it is already well fed. It will have been true then also and we can guess that predators and prey might have had a draught together when the latter were not hungry. Though the raptors are depicted as mindless killers in fiction and movies, it is unlikely to be true.

People are inclined not only to believe that dinosaurs lived at the same time as cave men but that all dinosaurs also lived at the same time. The dinosaurs writ large in Jurassic Park were actually Cretaceous dinosaurs, a later age. Stegosaurs were not shown, quite rightly, because they had already died out. The long existence on earth of the dinosaurs was itself subject to several mass extinctions and brontosaurs and stegosaurs had died out millions of years before the final demise of the dinosaurs. The truth is that warm-blooded species rarely live as long as ten million years. Since humans split from their nearest relatives, Chimpanzees, about 7 million years ago, plainly we do not have long to go—in geological terms. At the rate of environmental destruction we see about us, we’ll be lucky to live another millennium. We are already losing species faster than during the mass extinction that ended the span of the dinosaurs, 65 million years ago.

Dinosaur Metabolism

Middle aged humans tend to be broader and fatter than young ones. The same is true of other primates like gorillas and chimps, and indeed many mammals in general. The point is that older mammals have rather slower metabolic rates so that they put on bulk from the same food resources they had as youths to keep graceful. Did the dinosaurs have the same effect taken to extremes?

The examination of fossil dinosaur bones—histology—is beginning to show that dinosaurs were warm blooded or homeothermic—they had a mechanism for keeping their blood at a fairly constant temperature. Thus, measurements of isotopic oxygen in bones can reveal whether the bone was built up at a higher or lower temperature. If an animal has the same ratio for bones close to the skin and bones laid down inside the animal then it is likely to have been warm blooded. That is what is found in the bones of T rex.

Warm blooded baby dinosaurs, having little bulk and a relatively large surface would have had trouble keeping warm and probably were covered in downy hair. Adult dinosaurs were so large they would have had trouble—like an elephant or hippopotamus—keeping cool. If they reached maturity then their metabolism slowed down considerably, they would have been able to survive as if they were a cold blooded animal. They would have needed much less food and would have generated less internal heat to disperse. There were two good reasons why the earlier herbivorous dinosaurs tended to gigantism. First, their bulk will have deterred predators. Second, they would have been able to reach higher up trees for their sustenance. As trees grew bigger, the dinosaurs grew to match. But bigger herbivores meant that there was evolutionary pressure on the carnivores—they are bigger too.

Some 100 million years ago, there was an explosion of a new type of plant that had evolved just a few million years before—the flowering plants. They grew nearer the ground and the dinosaurs that specialised to eat them evolved more of the lifestyle of modern grazers and ruminants. Like modern grazers they sought protection in numbers and lived in herds—or should that be flocks if birds are their nearest relative?

Dinosaur Eggs

Roy Chapman Andrews was not really the first man to have discovered dinosaur eggs. Father Poeuch, a French amateur geologist, discovered some in the Pyrenees in 1859, although they were not identified as dinosaur eggs for another ten years. Sixty years later this was forgotten, or conveniently forgotten so that the American Museum of Natural History could announce the discovery to the world. Now 220 dinosaur egg sites are known in the world.

Recent work confirms that birds are dinosaurs but their adaptation to flight makes them quite untypical, so much remains yet to be discovered about their lifestyles. Studies of the nests of Maiasaur which built flat saucer shaped nests possibly covered in vegetation for warmth, show that the young could not walk—from their knee and ankle joints—but were eating vegetation—from teeth wear. The parents must have been bringing in food or regurgitating it. The eggs were placed in the nests so that they were not touching, and sometimes arranged in a spiral, suggesting that the parent took some care in placing them. The nests of a contemporary dinosaur, the Orodromeus, show that the hatchlings could walk like chicks but stayed near the nest.

The biggest eggs were not much bigger than a football. But hatchlings as big as a metre long were found in the nests suggesting that they must have grown that big in weeks rather than the two years it would take them if they were lizards. Baby reptiles are more or less miniature versions of the adults but mammals and birds have much bigger eyes making them look pretty to the mother. These baby dinosaurs had the same adaptation.

The poor Oviraptor, the egg eating dinosaur named by the 1920 expedition because it was found over a nest of eggs, turns out to have been a caring mother protecting her own eggs not trying to steal another’s. The eggs were assumed to have been of Protoceratops but in fact were not. The Oviraptor actually ate shellfish.

Cretaceous Arctic Temperatures

The latitude of the North Slope of Alaska in the Cretaceous was at least its present latitude of 70 degrees north and, from paleomagnetic measurements of sedimentary rocks in the foothills of the Brooks Range, it could have been as much as 85 degrees north. The situation was next to the Beaufort Sea, which played an ameliorating role in the delta’s climate, making it mild temperate and not colder. So the climate of the North slope seems to have been cool temperate, maritime; on the cool side, but with very little frost even in winter. Because of the high latitude, the winters had to be dark, and probably light was dim for part of the fall and spring.

But, by the Late Maastrichtian, most of the inland seas had receded. The seaway that extended from the Arctic to the Gulf of Mexico had indeed receded to a small remnant in the Western Interior U.S. by late Cretaceous. By the end of the Cretaceous the Arctic Ocean was isolated because the seaway receded and a connection with the Atlantic was closed--the Pacific connection did not reopen until about 3 million years ago, during the Pliocene. The Atlantic seaway looks like it was open around the Paleocene or Eocene. The first evidence of ice in the Arctic is in the Pliocene--Alaskan fossils indicate about 2.4 my for the first real frigid marine animals in the fossil record.

In fact the antarctic cap formed about early-mid eocene maybe as old as 45 Mya, but more likely about 35 Mya but the greenland cap is much later, probably about 5-10 Mya.

The shallow seas were probably the major factor in keeping more stable, less variable continental temperatures during the later Mesozoic. The middle Cretaceous is one of the greatest oceanic highstands in the last 500 million years, and even the Late Cretaceous was fairly flooded. So, if the sea level was so high, how could the Bering Strait have opened and closed so often to let all those dinosaurs cross over from Asia to North America and vice versa. If the Bering land bridge was mostly unavailable during the Late Cretaceous because of the high sea level, then the Mongolian and North American dinos of that time were not as closely related as we might think. Thought they might have been the same families it is doubtful they were the same genera, even in the case of Saurolophus osborni and Saurolophus angustirostris. Is there any evidence that the Bering land bridge was open during the Mesozoic after the Campanian?

Of course, the configuration of NE Siberia and Alaska during the Late Cretaceous is yet to be resolved. Alaska, and possibly Siberia, include a LOT of accreted terrain, so it is uncertain what the land looked like back then. Also, given the various orogenies going on in that region, even today, there is no sure way (save some intensive, yet-to-be done geologic and paleontologic field work) to establish when and where the Asia-American connection of the Late Cretaceous was extant.

The Nanxing basin is one of the few regions in which the K-T boundary is preseved on land. Outer Mongolian dinosaurs seem to be all Cretaceous. All the Late Cretaceous faunas of Mongolia may be 86-65 million years old.

What Is Science, Anyway?

Dr Thomas R Holtz Jr asks “What Is Science, Anyway?”. Science is NOT simply about describing natural things but is also about devising falsifiable hypotheses to explain the natural world. A scientific hypothesis must be falsifiable and if it can be shown to be wrong then it is naturally rejected. When scientists show hostility towards speculation what they are really hostile towards are untested, or untestable, hypotheses.

Hypotheses are a form of speculation. Pseudoscience and some less-than-rigorous science do not frame their hypotheses such that they could be tested. In palaeontology, the methods used to falsify our hypotheses are comparative anatomy, functional morphology, biomechanics, microscopic analyses, phylogenetic analyses, footprint analyses, etc. If the results of examination using these methods do not contradict the hypothesis, then it is accepted pending new data or techniques.

Some speculation is potentially falsifiable, although the data to test the hypotheses may not be immediately forthcoming, but dinosaurian research has attracted a lot of speculation which are not falsifiable. Some extinction hypotheses have been accepted even when the speculated events do not match the actual pattern of fossil distributions.

Carnivorous Plants

Such eminent people as Darwin have considered the pitcher plants as exclusively carnivorous, but one, the Purple Pitcher, when studied was found to have no digestive enzymes in its pitcher. The liquid it contained was a perfect little ecosystem of its own, supporting an healthy collection of plant and animal species. Normally the pitcher uses its "pitcher" as a trap. It looks like a flower and lures insects in to trap them on its slippery interior where they slide into a pool of digestive juices. This one instead bubbled in oxygen to aerate the water and allow its microfauna to thrive. In return it got a richer supply of carbon dioxide and the nutrtious droppins of its tiny guests. It achieved a similar result to the carnivorous pitcher plant in a benign way.

Another pitcher plant, Nepenthes bicalcarata, has a bulbous pitcher with a pair of sharp looking spikes hanging over its entrance. Insects bypass them and find themselves trapped only to slip into the mire. Yet, a species of ant knows how to fish out the dead carcasses with no harm to themselves. This is not merely an enterprising ant because the plant actively encourages its guest by providing a home for them in the hollow stalk that connects the pitcher to the plant. What does the plant get out of the symbiosis—apparently protection from genuine marauders. When some animal tries to fish a morsel out, the ants collectively rattle the rim of the pitcher until the enemy withdraws in alarm from the noise. So the plant no longer has the protein—the ants get that as a prize—but instead has protection.

Many carnivorous plants, like Australian sundews, are only carnivorous in the wet season when the nutrients in the water are too dilute to be useful. In the dry season, they feed like any other photosynthesising plant. The tryphyophyllum vine of Sierra Leone is more exclusive still, only eating animal protein just before it flowers.

Pitchers have other ways of cheating. The sun pitchers of the table mountains of Venezuela are like iced cream cones up to a foot high. They are simply a spirally curled up leaf to catch the rain and mist. Botanists however found they too lacked digestive enzymes in the liquid that collected. Nevertheless, they consumed the insects by working symbiotically with various bacteria which digested the insects for them. Possibly through evolution, they will develop their own chemicals for digesting their victims.

In Peru there are varieties of potato and tomato with hairs so sticky they are always covered in a layer of dead insect carcasses. Presumably, they digest them, though it might be simply a defence. Attempts are being made to introduce the sticky leaf strain into ordinary potatoes to protest them against pests like capsid bugs. Even carnivorous algae have been found. They have a filament they use for propulsion but can also use it to fish for titbits like bacteria that they bundle up and eat.

The germinating seed of shepherd’s purse exudes a sticky fluid that is attractive to small insects. They trap them and digest them thus speeding up their maturation. Even the London Pride saxifrage and the petunia have some digestive enzymes in the sticky leaf traps they possess. Thus they catch and digest some small insects as a contribution to their needs. Plainly carnivorous plants are more common than imagined.

Some of these notes are abstracted from the website, Dinosauria On-line. Readers wanting more detail are referred to the original items posted on the website which has a wealth of dinosaur information for both dinosaur amateurs and enthusiasts alike, aims to give the reader a broad exposure to dinosaur science and provides a forum for topical discussion. Discover the links between Archaeopteryx and modern birds and find out why the dinosaur DNA find claim may be a mistake. There is a link to the Dinosaur Electronic Mailing List and real enthusiasts can order a replica oviraptor egg for their mantlepiece.

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