Sunday, October 31, 2010

October 31, 2010 : Hydra (Myth)


In Greek mythology, the Lernaean Hydra (Greek: Λερναία Ὕδρα) was an ancient nameless serpent-like chthonic water beast (as its name evinces) that possessed nine heads — and for each head cut off it grew two more — and poisonous breath so virulent even her tracks were deadly. The Hydra of Lerna was killed by Heracles as one of his Twelve Labours. Its lair was the lake of Lerna in the Argolid, though archaeology has borne out the myth that the sacred site was older even than the Mycenaean city of Argos since Lerna was the site of the myth of the Danaids. Beneath the waters was an entrance to the Underworld, and the Hydra was its guardian.

After slaying the Nemean lion, Eurystheus sent Heracles to slay the Hydra, which Hera had raised just to slay Heracles. Upon reaching the swamp near Lake Lerna, where the Hydra dwelt, Heracles covered his mouth and nose with a cloth to protect himself from the poisonous fumes. He fired flaming arrows into its lair, the spring of Amymone, a deep cave that it only came out of to terrorize neighboring villages. He then confronted it, wielding a harvesting sickle (according to some early vase-paintings), a sword or his famed club. Ruck and Staples (1994: 170) have pointed out that the chthonic creature's reaction was botanical: upon cutting off each of its heads he found that two grew back, an expression of the hopelessness of such a struggle for any but the hero, Hercules. The weakness of the Hydra was that only one of its heads was immortal.

Saturday, October 30, 2010

October 30, 2010 : Plesiosaur (Extinct)


A plesiosaur (pronounced /ˈpliːsiəsɔər/; Greek: plēsios/πλησιος 'near' or 'close to' and sauros/σαυρος 'lizard') was a type of carnivorous aquatic (mostly marine) reptile. After their discovery, plesiosaurs were somewhat fancifully said to have resembled "a snake threaded through the shell of a turtle", although they had no shell. The common name "plesiosaur" is applied both to the "true" plesiosaurs (Superfamily Plesiosauroidea), which include both long-necked (elasmosaurs) and short-necked (polycotylid) forms, and to the larger taxonomic rank of Plesiosauria, which includes the pliosaurs. The pliosaurs were the short-necked, large-headed plesiosaurians that were the apex predators for much of the Mesozoic.

Plesiosaurs (sensu Plesiosauroidea) appeared at the start of the Jurassic Period and thrived until the K-T extinction, at the end of the Cretaceous Period. While they were Mesozoic diapsid reptiles that lived at the same time as dinosaurs, they were neither dinosaurs nor archosaurs.

Plesiosaurs had a broad body and a short tail. They retained their ancestral two pairs of limbs, which evolved into large flippers. Plesiosaurs evolved from earlier, similar forms such as pistosaurs or very early, longer-necked pliosaurs. There are a number of families of plesiosaurs, which retain the same general appearance and are distinguished by various specific details. These include the Plesiosauridae, unspecialized types which are limited to the Early Jurassic period; Cryptoclididae, (e.g. Cryptoclidus), with a medium-long neck and somewhat stocky build; Elasmosauridae, with very long, inflexible necks and tiny heads; and the Cimoliasauridae, a poorly known group of small Cretaceous forms. According to traditional classifications, all plesiosaurs have a small head and long neck but, in recent classifications, one short-necked and large-headed Cretaceous group, the Polycotylidae, are included under the Plesiosauroidea, rather than under the traditional Pliosauroidea. Size of different plesiosaurs varied significantly, with an estimated length of Trinacromerum being three meters and Mauisaurus growing to twenty meters.

Friday, October 29, 2010

October 29, 2010 : Mosasaur (Extinct)


Mosasaurs (from Latin Mosa meaning the 'Meuse river', and Greek sauros meaning 'lizard') are large extinct marine lizards. The first fossil remains were discovered in a limestone quarry at Maastricht on the Meuse in 1764. Mosasaurs are now considered to be the closest relatives of snakes, due to cladistic analyses that have taken into account similarities in jaw and skull anatomies. Mosasaurs were varanoids closely related to terrestrial monitor lizards. They probably evolved from semi-aquatic squamates known as aigialosaurs, which were more similar in appearance to modern-day monitor lizards, in the Early Cretaceous. During the last 20 million years of the Cretaceous Period (Turonian-Maastrichtian), with the extinction of the ichthyosaurs and pliosaurs, mosasaurs became the dominant marine predators.

Mosasaurs breathed air, were powerful swimmers, and were well-adapted to living in the warm, shallow epicontinental seas prevalent during the Late Cretaceous Period. Mosasaurs were so well adapted to this environment that they gave birth to live young, rather than return to the shore to lay eggs, as sea turtles do.

The smallest-known mosasaur was Carinodens belgicus, which was about 3.0 to 3.5 m long and probably lived in shallow waters near shore, cracking mollusks and sea urchins with its bulbous teeth. Larger mosasaurs were more typical: mosasaurs ranged in size up to 17 m. Tylosaurus holds the record for longest mosasaur, at 17.5 m.

Thursday, October 28, 2010

October 28, 2010 : Nectocaris (Extinct)


Nectocaris is a genus containing one species (
N. pteryx) of early cephalopod known from the Middle Cambrian Burgess Shale. Walcott, the discoverer of the shale, had photographed the one specimen he had collected in the 1910s, but never had time to investigate it further. It was not until 1976 that it was formally described, by Simon Conway Morris. The head had two stalked eyes, one pair of tentacles, and a flexible siphon underneath its body. Fleshy fins supported by internal spines ran along the sides of the flattened, kite-shaped body.

Because the genus was only known from a single specimen, Conway Morris was unable to deduce its affinity. It had some features which were reminiscent of the arthropods, but these could well have been convergently derived. Its fins were very unlike the arthropods. Working from photographs, the Italian palaeontologist Alberto Simonetta believed he could classify
Nectocaris within the chordates. He focussed mainly on the tail and fin morphology, interpreting Conway Morris's 'gut' as a notochord - a distinctive chordate feature. However, his case was unconvincing, and its classification remained uncertain until 2010, when Martin Smith and Jean-Bernard Caron described 91 additional specimens, many better preserved than the type. These allowed them to reinterpret Nectocaris as a primitive cephalopod, with two tentacles instead of the 8 or 10 of modern cephalopods. The structure previous researchers had identified as an oval carapace or shield behind the eyes was shown to actually be a soft funnel, similar to the ones used for propulsion by modern cephalopods. The interpretation would push back the origin of cephalopods by at least 30 million years, much closer to the first appearance of complex animals, in the Cambrian explosion.

Nectocaris was a free-swimming, predatory or scavenging organism, possibly occupying a niche similar to the arrow worms. This lifestyle is honoured in its binomial name:
Nectocaris means "swimming crab" (Latin pteryx means "fin").

Wednesday, October 27, 2010

October 27, 2010 : Anomalocaris (Extinct)


Anomalocaris ("abnormal shrimp") is an extinct genus of anomalocaridid, which are, in turn, thought to be closely related to the arthropods. The first fossils of
Anomalocaris were discovered in the Ogygopsis Shale by Joseph Frederick Whiteaves, with more examples found by Charles Doolittle Walcott in the famed Burgess Shale. Originally several fossilized parts discovered separately (the mouth, feeding appendages and tail) were thought to be three separate creatures, a misapprehension corrected by Harry B. Whittington and Derek Briggs in a 1985 journal article.

Anomalocaris has been misidentified several times, in part due to its makeup of a mixture of mineralized and unmineralized body parts; the mouth and feeding appendage was considerably harder and more easily fossilized than the delicate body. Its name originates from a description of a detached 'arm', described by Joseph Frederick Whiteaves in 1892 as a separate crustacean-like creature due to its resemblance to the tail of a lobster or shrimp.

The first fossilized mouth was discovered by Charles Doolittle Walcott, who mistook it for a jellyfish and placed the genus Peytoia. Walcott also discovered a second feeding appendage but failed to realize the similarities to Whiteaves discovery and instead identified it as feeding appendage or tail of the extinct Sidneyia. The body was discovered separately and classified as a sponge in the genus Laggania; the mouth was found with the body, but was interpreted by its discoverer Simon Conway Morris as an unrelated Peytoia that had through happenstance settled and been preserved with Laggania. Later, while clearing what he thought was an unrelated specimen, Harry B. Whittington removed a layer of covering stone to discover the unequivocally connected arm thought to be a shrimp tail and mouth thought to be a jellyfish. Whittington linked the two species, but it took several more years for researchers to realize that the continuously juxtaposed Peytoia, Laggania and feeding appendage actually represented a single, enormous creature.

According to International Commission on Zoological Nomenclature rules, the oldest name takes priority, which in this case would be Anomalocaris. The name Laggania was later used for another genus of anomalocarid. "Peytoia" has been modified into Parapeytoia, a genus of Chinese anomalocarid. Anomalocaris is placed in the extinct family Anomalocaridae, and is now considered to be related to modern arthropods.

Tuesday, October 26, 2010

October 26, 2010 : Brontoscorpio (Extinct)


Brontoscorpio anglicus ("English thunder scorpion") was a 1-metre long aquatic scorpion that lived during the Silurian period. When alive,
B. anglicus would have resembled an oversized scorpion, albeit with relatively large (for a scorpion) compound eyes; it was an important predator of its time, given that the arthropods were among the largest animals on Earth during the Silurian.

All post-Paleozoic scorpions are terrestrial, while during the Silurian many of the known taxa made the transition from aquatic to terrestrial environments. It has been inferred that Brontoscorpio was capable of leaving the water and entering land, whether to evade other predators, such as large nautiloids, eurypterids, or even other aquatic scorpions; or pursue prey, such as other, smaller terrestrial scorpions. However, given its great size, B. anglicus had to return to the water when it tired of supporting its own weight, or at the very least whenever it moulted its exoskeleton (on land, it would risk being crushed by its own mass). Marine scorpions such as B. anglicus captured, stung, and ate small sea animals such as fish like acanthodians, heterostracans, smaller scorpions and trilobites.

As with other arachnids, such as modern scorpions, Brontoscorpio respired through gas exchange via pores in its exoskeleton and the inner linings of its book lungs. Its tail was tipped with a large, venomous stinger that was, according to Walking with Monsters, the size of a light bulb.

Monday, October 25, 2010

October 25, 2010 : Delphyodontos dacriformes (Extinct)

Delphyodontos dacriformes

Delphyodontos dacriformes was a prehistoric holocephalid fish from the early Carboniferous, from the Bear Gulch Limestone Lagerstätte, in Montana. Its fossils consist mainly of aborted fetuses or newly hatched young. Sharp teeth and fecal matter in the fossils suggests that
Delphyodontos practiced intrauterine cannibalism, like some modern sharks, such as gray reef sharks.

According to the fossils, the recently born would have resembled tadpoles with small, but sharp beaks. Because of the evidence suggesting intrauterine cannibalism, D. dacriformes is assumed to have been carnivorous, though, besides siblings, it is unknown what other organisms they would have eaten.

The generic name, Delphyodontos, means "womb tooth," in reference to the sharp, beak-like teeth and their possible habits of intrauterine cannibalism. The specific name, dacriformes, refers to the teardrop-shaped body.

Sunday, October 24, 2010

October 24, 2010 : Pteraspis (Extinct)


Pteraspis (meaning
wing shield) is an extinct genus of primitive jawless fish that lived in the Devonian period of what is now Britain and Belgium.

Like other heterostracan fishes, Pteraspis had a protective armored plating covering the front of its body. Though lacking fins other than its lobed tail, it is thought to have been a good swimmer thanks to stiff, wing-like protrusions derived from the armoured plates over its gills. This, along with the horn-like rostrum, made Pteraspis very streamlined in shape; a perfect quality for a good swimmer. Pteraspis also had some stiff spikes on its back, possibly an additional form of protection against predators. It is thought to have fed from shoals of plankton just under the ocean surface.

Pteraspis grew to a length of 8 inches (20 centimeters).

Saturday, October 23, 2010

October 23, 2010 : Harpagofututor (Extinct)


Harpagofututor is an extinct genus of cartilaginous fish from the Mississippian of North America.

It was an eel-shaped fish with almost no scales. About eight inches long, it swam with some help from its fins, but also relied on whole-body locomotion to move. The fish also had teeth sufficient for eating shellfish.

Harpagofututor is thought to be related to the cochliodonts, chimaeroids, and
Chondrenchelys problematica.

The fish was discovered in the 1980s in Montana's Bear Gulch area by Adelphi University palaeontologist Richard Lund, who has been exploring the limestone formations of the region since 1969. The area was thought to be the location of a shallow bay. Fish remains are found throughout the area. Further examinations of the soft tissue pigments of these fossilized remains led to more information about the fish and information about its internal organs, including its reproductive system.

Friday, October 22, 2010

October 22, 2010 : Leviathan (Myth)


Leviathan (pronounced /lɨˈvaɪ.əθən/; Hebrew: לִוְיָתָן, Modern 
Livyatan Tiberian Liwyāṯān ; "twisted, coiled"), is a sea monster referred to in the Bible. In Demonology, Leviathan is one of the seven princes of Hell and its gatekeeper (see Hellmouth). The word has become synonymous with any large sea monster or creature. In classical literature (such as the novel Moby-Dick) it refers to great whales, and in Modern Hebrew, it means simply "whale."

Leviathan and similar serpent-demons have a long history in ancient Near Eastern mythology, with a seven-headed serpent being overcome by a hero-god being attested as early as the 3rd millennium BCE in Sumerian iconography. The same chaos-combat theme appears on 2nd millennium Syrian seals, where the storm-god is shown in combat with a serpent, and in the Ugarit tablets, where the sea-monster Lotan was one of the helpers of the sea-god Yamm in his battle with the weather-god Haddad Baal. In the Ugaritic texts Lotan, or possibly another of Yamm's helpers, is given the epithets "wriggling serpent" and "mighty One with the seven heads," and Isaiah 27:1 uses the first of these phrases to describe Leviathan, although in this case the name "Leviathan" apparently refers to an unnamed historical/political enemy of Israel rather than the original serpent-monster. In Psalm 104 Leviathan is not described as harmful in any way, but simply as a creature of the ocean, part of Yahweh's creation. In Job 41:2-26, on the other hand, he is definitely a crocodile-monster to be feared - the author appears to have based the passage on Egyptian animal mythology, where the crocodile is the enemy of the sun-god, but in contrast both to this source and to the Syrian chaos-battle he does not represent the image in terms of mythological combat.

Thursday, October 21, 2010

October 21, 2010 : Scapanorhynchus (Extinct)


Scapanorhynchus ("Spade Snout") is an extinct genus of shark from the Cretaceous era. Their extreme similarities to the living goblin shark,
Mitsukurina owstoni, lead some experts to consider reclassifying it as Scapanorhynchus owstoni. However, most shark specialists regard the goblin shark to be distinct enough from its prehistoric relatives to merit placement in its own genus.

Scapanorhynchus had an elongated, albeit, flattened snout, and sharp awl-shaped teeth, ideal for seizing fish, or tearing chunks of flesh from its prey.

Wednesday, October 20, 2010

October 20, 2010 : Astraspis (Extinct)


Astraspis ('star shield') is an extinct genus of primitive jawless fish from the Ordovician of Central North America and Bolivia (Gagnier, 1993) . It is related to other Ordovician fishes, such as the South American Sacabambaspis, and the Australian Arandaspis.

Astraspids are hypothesized to have been about 200mm in length. They are supposed to have had a mobile tail covered with small protective plates (<1mm) and a head region covered with much larger plates (>>2mm). The specimen from North America (described by Sansom et al., 1997) is to have had relatively large, lateral eyes and a series of eight gill openings on each side. The specimen was generally oval in cross-section. The protective bony plates covering the animal were composed of aspidin (chemically similar to modern shark's teeth), covered by tubercles composed of dentine. It is from these tubercles (which are generally star-shaped) that the name 'Astraspis' (literally "star-shield") is derived.

Tuesday, October 19, 2010

October 19. 2010 : Iniopteryx (Extinct)


Iniopteryx ("Nape Wing") is an extinct genus of cartilaginous fish. It is from the Pennsylvanian epoch of the Carboniferous period, approximately 300 million years ago. Their fossils have been found in North America, primarily in two states: Ohio and Montana. In general, very little is known about this species.

Iniopteryx was a plump, small-sized chiemaera-like fish. It is known that the species average size was around half a meter long in length. While the species had specialized spines and fins similar to that of a flying fish. It is possible that it could glide through the air just like them. However, it is accepted by Scientists and Paleontologists that Iniopteryx was indeed a fish that was the bottom-dwelling kind.

Monday, October 18, 2010

October 18, 2010 : Jamoytius kerwoodi (Extinct)

Jamoytius kerwoodi

Jamoytius kerwoodi was a species of primitive, eel-like jawless fish that lived in the Silurian period.

J. kerwoodi is the earliest known anaspid.. It had long, paired fins running along its body - making it a good swimmer.
J. kerwoodi resembled a lamprey, especially with its rounded mouth and elongated body. However, as it had no teeth or teeth-like structures in its mouth, it was not carnivorous like its distant modern-day relative, the lamprey. It was more likely to have been a filter-feeder or a detrius-feeder, possibly in the manner of larval lampreys.

The fish had a cartilaginous skeleton, and a branchial basket resembling the cyclostomes - used to suggest that it was a near-ancestor to that clade. It is also the earliest known vertebrate with camera-type eyes. It also possessed weakly mineralised scales.

Sunday, October 17, 2010

October 17, 2010 : Psarolepis (Extinct)


Psarolepis (pronounced /sæˈrɒlɨpɨs/,
psārolepis, from Greek ψαρός 'speckled' and λεπίς 'scale') is a genuslobe-finned fish which lived around 397 to 418 million years ago (Pridoli to Lochkovian stages). Fossils of of extinct Psarolepis have been found mainly in South China and described by paleontologist Xiaobo Yu in 1998. It is not known certainly in which group Psarolepis belongs, but paleontologists agree that it probably is a basal genus and seems to be close to the common ancestor of lobe-finned and ray-finned fishes. In 2001, paleontologist John A. Long compared Psarolepis with Onychodontiform fishes and refer to their relationships.

Psarolepis had a pair of 'parasymphysical tooth whorls', teeth which extend up at the front of the lower jaw. The head was made of several thick dermal plates and covered with deep pock-marks and large pores. Another trait is a large pectoral spine, just in front of the pectoral fin, extending back from the shoulder girdle, and a dorsal spine located in front of a median fin behind the head, which gives the fish a shark-like form.

The pock-marked head of Psarolepis was made of plates containing a layer of porcelain-like cosmine. Because the cosmine layer obscures the suture lines of the skull, it is difficult to study the exact bone structure. The snout was strangely humped and the nostrils were located above the eyes, which were just above the upper jaw.

The most spectacular findings were the fin spines. Two are known: one extending back from the shoulder girdle and another which is associated with the dorsal fin. These fin spines are found only in primitive jawed fishes and are apparently absent from the most primitive sharks, but present in abundance in more derived forms.

Psarolepis had teeth at the very front of the snout with large fangs on the tooth plate. Outstanding feature are the 'parasymphysical tooth whorls' which place the fish in the order of onychodontida. The premaxilla and the dentary had large inner teeth and irregular array of tiny outer teeth.

Saturday, October 16, 2010

October 16, 2010 : Giant Orthocone (Extinct)

Giant Orthocone

The partial shell of one giant Cameroceras yielded a total length estimated at the time at nearly 30 feet (9 m). (This estimate has since been revised downward quite a bit.) Regardless of this estimate's degree of accuracy, this gargantuan cephalopod was one of the largest animals ever to live during the Paleozoic Era, if not the largest. Judging from its huge size, it was likely an apex predator that lived in deeper water (it would possibly have been unable to maneuver in shallow water), and probably fed on eurypterids such as Megalograptus, large trilobites, and smaller cephalopods. The program "Chased by Sea Monsters" speculatively suggests that it was largely blind, having large, yet feeble eyes like those of what may be its closest living relative, Nautilus.

"Cameroceras" has become a catch all term, or "wastebasket taxon," for any large orthoconic endocerid such as Endoceras, Vaginoceras, Meniscoceras, and even Cameroceras as a described genus. Although Cameroceras trentonense was first described by Conrad for the species in 1842 since then the generic term has had variable meaning. Hall, who named and described Endoceras in 1847 recognized Cameroceras trentonense specifically but used Endoceras for other species of large endocerids from the Trenton Limestone of western New York state.

"Cameroceras" and "Endoceras" may even apply to different stages of the same species. Although Cameroceras takes precedence where the two refer to the same species, its vague application leaves Endoceras or other well described genus the term of choice.

Friday, October 15, 2010

October 15, 2010 : Karkinos (Myth)


In Greek mythology, Karkinos or Carcinus (a transliteration of the Greek word for "crab") was a crab that came to the aid of the Lernaean Hydra as it battled Heracles, bottom left. Karkinos bit Heracles in the foot, but was crushed beneath the hero's heel. For its efforts, however, Hera placed the crab amongst the stars as the constellation Cancer. It is one of a large number of constellations that memorialise the labours of Heracles. The Karkinos is mentioned in the Bibliotheca of Pseudo-Apollodorus, the Euthydemus of Plato, and the Astronomica of Pseudo-Hyginus.

Thursday, October 14, 2010

October 14, 2010 : Enchodus (Extinct)


Enchodus is an extinct genus of bony fish. It flourished during the Upper Cretaceous and was small to medium in size. One of the genus' most notable attributes are the large "fangs" at the front of the upper and lower jaws and on the palatine bones, leading to its misleading nickname among fossil hunters and paleoichthyologists, "the saber-toothed herring". These fangs, along with a long sleek body and large eyes, suggest
Enchodus was a predatory species.

The largest-known species of Enchodus is E. petrosus, remains of which are common from the Niobrara Chalk, the Mooreville Chalk Formation, the Pierre Shale, and other geological formations deposited within the Western Interior Seaway and the Mississippi Embayment. Large individuals of this species had fangs measuring 6+ cm in length, though the total body length was only about 1.5 meters, giving its skull an appearance somewhat reminiscent of modern deep-sea fishes, such as anglerfish and viperfish. Other species were smaller, some like E. parvus were only some cm (a few inches) long.

Despite being a formidable predator, remains of Enchodus are commonly found among the stomach contents of larger predators, including sharks, other bony fish, mosasaurs, plesiosaurs and seabirds such as Baptornis advenus.

In North America, Enchodus remains have been recovered from most states with fossiliferous Late Cretaceous rocks, including Kansas, Nebraska, Colorado, Alabama, Mississippi, Georgia, Tennessee, Wyoming, Texas, California, and New Jersey. The taxon is also known from coeval strata in Africa, Europe, and southwest Asia. Enchodus survived the Cretaceous–Tertiary extinction event and persisted at least into the Eocene. It was found all over the world.

Wednesday, October 13, 2010

October 13, 2010 : Edestus (Extinct)


Edestus is a genus of shark that lived throughout the world's oceans during the late Carboniferous. All of the species are known only from their teeth. The term "edestid" is often used to refer to any or all members of the order Eugeneodontiformes, though, strictly speaking, "edestid" should be used only to refer to members of the family Edestidae.

Like its other relatives, such as Helicoprion, and unlike modern sharks, the species of
Edestus grew teeth in curved brackets, and did not shed the teeth as they became worn. In Edestus' case, there was only a single row of teeth in each jaw, so that the mouth would have resembled a monstrous pair of pinking shears. The degree of curvature in the teeth brackets, along with size are distinct in each species.

Because the teeth are sharp and serrated, all of the species are presumed to have been carnivorous. Exactly how they captured, or even ate, their prey, along with their appearance, remains pure speculation until a more complete fossil, or skull, is found.

Edestus giganteus, (also known as the "scissor-tooth shark") lived in the oceans during the Late Carboniferous (306-299 million years ago).

Little is known about
E. giganteus apart from a single set of teeth currently housed in the American Museum of Natural History in New York City. Paleontological studies suggest that E. giganteus, unlike modern-day sharks, did not shed worn or broken teeth. Rather, it continued growing new teeth and gums near the back of the mouth, eventually pushing the older teeth and gums forward, until they protruded from the mouth. It is not clear what function the strange teeth performed.

E. giganteus grew to about the size of the modern-day great white shark, thus probably making it one of the top sea predators of its day. As with all other members of the genus, it is not clear how
E. giganteus caught or ate its prey, however.

Tuesday, October 12, 2010

October 12, 2010 : Pituriaspis (Extinct)


Pituriaspis doylei ("Doyle's Pituri Shield") was one of two known species of jawless fish belonging to the Class Pituriaspida, and is the better known of the two. The species lived in estuaries during the Middle Devonian, in what is now the Georgina Basin of Western Queensland, Australia.

The first specimens of P. doylei were actually empty sandstone casts of the head shields, with none of the original bone remaining.

P. doylei vaguely resembled the Osteostraci, though neither are considered to be close relatives. The headshield extends posteriorly to form a long abdominal division which probably reached the anal region. The dorsal portion of its head armor differs from osteostracans in that the orbits of the eyes are set apart from each other, and that the shield has no pineal foramen (the "hole" between the eyes of
Cephalaspis and its relatives), and that an opening at the base of the rostrum gives very little hints about the nature of the nasal openings. The exoskeleton is ornamented with tiny rounded tubercles. A unique characteristic of the Pituriaspida is a peculiar pit, which may have held some sort of sensory organ in life, located ventrally to the orbits, known as the adorbital depression. Almost nothing is known of the rest of the body, save that it had a pair of well-developed pectoral fins, similar to gnathostome fish.

Monday, October 11, 2010

October 11, 2010 : Jormungand (Myth)


In Norse mythology, Jörmungandr (pronounced [ˈjœrmuŋɡandr]), mostly known as Jormungand, or Jörmungand(Old Norse: Jǫrmungandr), or Midgard Serpent (Old Norse: Midgarðsormr), or World Serpent, is a sea serpent, and the middle child of the giantess Angrboða and the god Loki. According to the Prose Edda, Odin took Loki's three children, Fenrisúlfr, Hel and Jörmungandr, and tossed Jörmungandr into the great ocean that encircles Midgard. The serpent grew so large that he was able to surround the Earth and grasp his own tail. When he lets go the world will end. As a result he earned the alternate name of the Midgard Serpent or World Serpent. Jörmungandr's arch enemy is the god Thor.

The major sources for myths about Jörmungandr are the Prose Edda, Húsdrápa, Hymiskviða, and Völuspá. Less important sources include kennings in skaldic poetry. For example in Þórsdrápa, faðir lögseims, "father of the sea-thread", is used as a kenning for Loki. There are also image stones from ancient times depicting the fishing encounter.

Sunday, October 10, 2010

October 10, 2010 : Sacabambaspis (Extinct)


Sacabambaspis is an extinct genus of jawless fish that lived in the Ordovician period. It is related to Astraspis. 

Sacabambaspis had a head shield made from a large upper (dorsal) plate that rose to a slight ridge in the midline, and a deep curved lower (ventral) plate. Also it had narrow branchial plates which link these two along the sides, and cover the gill area. The rest of body was covered by long, strap-like scales behind the head shield. The eyes were far forward and between them are possibly two small nostrils, and the mouth was armed with very thin plates (oral plates).

The fossils of Sacabambaspis and Astraspis show clear evidence of a sensory structure (lateral line system). The arrangement of these organs in regular lines allows the fish to detect the direction and distance from which a disturbance in the water is coming.

Saturday, October 9, 2010

October 9, 2010 : Stethacanthus (Extinct)


Stethacanthus is an extinct genus of shark which lived in the Late Devonian and Early Carboniferous epochs, around 360 million years ago. Fossils have been found in Europe and North America.

Stethacanthus was around 70 centimetres (2.3 ft) long, and in many respects, had a typical shark-like appearance. However, it is best known for its unusually shaped dorsal fin, which resembled an anvil or ironing board. Small spikes (enlarged versions of the dermal denticles commonly covering shark skin) covered this crest, and the shark's head as well. The crest may have played a role in mating rituals, or used to frighten potential predators.

Friday, October 8, 2010

October 8, 2010 : Cymbospondylus (Extinct)


Cymbospondylus ( A Greek word meaning "
Boat Spine") was a basal early ichthyosaur that lived between the middle and later years of the Triassic period (240-210 million years ago). Previously, the genus was classified as a shastasaurid, however, more recent work finds it to be more basal.

Fossils have been found in both Germany and Nevada, and the first species was named by Joseph Leidy in 1868. It was not until the early 1900s that the first complete skeletons were discovered. Fossil vertebrae from Cymbospondylus were allegedly used as plates by Nevada's silver miners; it is now the state's official fossil. 

Cymbospondylus was one of the largest ichthyosaurs, with fossils ranging from 6 to 10 metres (20 to 33 ft) long. It was also one of the least fish-like of the ichthyosaurs, lacking a dorsal fin and fluked tail. It did, however, have an elongated snout like other ichthyosaurs.

Despite its size, Cymbospondylus would not have been much of a threat to other marine reptiles, such as Nothosaurus. The one metre long head, with large jaws, contained rows of teeth which were so small that they could not have grasped and held on to large animals, let alone kill them. Instead, the teeth appear to have been adapted for catching and holding on to small and medium-sized fish, belemnites, and cephalopods such as ammonites. The long tail would have been excellent for swimming, and allowed Cymbospondylus to move at fast speeds and efficiently hunt down shoals of swimming fish.

Adult Cymbospondylus probably spent much of their time hunting in deep offshore water, only venturing into shallower water to breed or to catch seasonally available prey. Like other ichthyosaurs, Cymbospondylus probably gave birth to live young, as it had no way to lay eggs. These, on reaching adult size, probably had few, if any, predators that could harm them.

The eel-like tail of Cymbospondylus made up almost half the total body length, and it is possible that the tail was used as a primary swimming mechanism. Like present day sea snakes, Cymbospondylus probably swam by wriggling its body from side to side. The paddle-like limbs of Cymbospondylus would primarily have been underwater stabilizers, and for slowing down the ichthyosaur's swimming speed.

Thursday, October 7, 2010

October 7, 2010 : Kraken (Myth)


Kraken (pronounced /ˈkreɪkən/ or /ˈkrɑːkən/) are mythical sea monsters of gargantuan size, said to have dwelt off the coasts of Norway and Iceland. The sheer size and fearsome appearance attributed to the beasts have made them common ocean-dwelling monsters in various fictional works (see Kraken in popular culture). The legend may actually have originated from sightings of real giant squid that are variously estimated to grow to 13–15 m (40–50 ft) in length, including the tentacles. These creatures normally live at great depths, but have been sighted at the surface and have reportedly attacked ships.

Kraken may be derived from the Old Norse noun
kraka "to drag under the water". In modern German, Krake (plural and declined singular: Kraken) means octopus, but can also refer to the legendary Kraken.

Even though the name kraken never appears in the Norse sagas, there are similar sea monsters, the hafgufa and lyngbakr, both described in Örvar-Odds saga as a giant spider-creature. The Norwegian text from c. 1250, Konungs skuggsjá. Carolus Linnaeus included kraken as cephalopods with the scientific name Microcosmus in the first edition of his Systema Naturae (1735), a taxonomic classification of living organisms, but excluded the animal in later editions. Kraken were also extensively described by Erik Pontoppidan, bishop of Bergen, in his "Natural History of Norway" (Copenhagen, 1752–3). Early accounts, including Pontoppidan's, describe the kraken as an animal "the size of a floating island" whose real danger for sailors was not the creature itself, but the whirlpool it created after quickly descending back into the ocean. However, Pontoppidan also described the destructive potential of the giant beast: "It is said that if it grabbed the largest warship, it could manage to pull it down to the bottom of the ocean" (Sjögren, 1980). Kraken were always distinct from sea serpents, also common in Scandinavian lore (Jörmungandr for instance).

Wednesday, October 6, 2010

October 6, 2010 : Megalodon (Extinct)


The megalodon, Carcharodon or Carcharocles megalodon (pronounced /ˈmɛɡələdɒn/MEG-ə-lə-don, "big tooth" in Greek, from μέγας and ὀδούς) is an extinct megatoothed shark that existed in prehistoric times, from the Oligocene to Pleistocene epochs, approximately 25 to 1.5 million years ago.

C. megalodon may have been the largest and most powerful macro-predatory fish that ever lived. Fossil remains of
C. megalodon indicate that it possibly approached a maximum of around 20.3 metres (67 ft) in length. C. megalodon has been assigned to the order Lamniformes but its phylogeny is disputed. Scientists suggest that C. megalodon looked like a stockier version of the great white shark, Carcharodon carcharias, in life. Fossil evidence confirms that C. megalodon had a cosmopolitan distribution. C. megalodon was a super-predator, and bite marks on fossil bones of its victims indicate that it preyed upon large marine animals.

According to Renaissance accounts, huge, triangular fossil teeth often found embedded in rocky formations were once believed to be petrified tongues, or glossopetrae, of the dragons and snakes. This interpretation was corrected in 1667 by a Danish naturalist, Nicolaus Steno, who recognized them as ancient shark teeth (and famously produced a depiction of a shark's head bearing such teeth). He mentioned his findings in a book, The Head of a Shark Dissected, which also contained an illustration of a C. megalodon tooth, previously considered to be a tongue stone.

A Swiss naturalist, Louis Agassiz, gave this shark its scientific name, Carcharodon megalodon, in 1835, in his research work Recherches sur les poissons fossiles (Research on fossil fish), which he completed in 1843. The teeth of the C. megalodon are morphologically similar to the teeth of the great white shark. On the basis of this observation, Agassiz assigned the genus Carcharodon to the megalodon. While the scientific name is C. megalodon, it is often informally dubbed the megatooth shark or giant white shark or even monster shark.

Tuesday, October 5, 2010

October 5, 2010 : Platecarpus (Extinct)


Platecarpus ("Flat wrist") is an extinct genus of aquatic lizard belonging to the mosasaur family, living around 75 million years ago during the end of the Cretaceous period. Fossils have been found in Belgium and the United States as well as a possible specimen in Africa.
Platecarpus probably fed on fish, squid, and ammonites. Like other mosasaurs, it was initially thought to have swum in an eel-like fashion, although a recent study suggests that it swam more like modern sharks. An exceptionally well-preserved specimen of P. tympaniticus known as LACM 128319 shows skin impressions, pigments around the nostrils, bronchial tubes and the presence of a high profile tail fluke, showing that it and other mosasaurs did not necessarily have an eel-like swimming method but were more powerful fast swimmers. It is held in the Natural History Museum of Los Angeles County.

Platecarpus had a long, down-turned tail with a large dorsal lobe on it, steering flippers, and jaws lined with conical teeth. It grew up to 4.3 metres (14 ft) long, with half of that length taken up by its tail. The platecarpine mosasaurs had evolved into the very specialized plioplatecarpine group by the end of the Cretaceous.

Platecarpus was probably the most common genus of mosasaur in the Western Interior Sea during the deposition of the Smoky Hill Chalk in Kansas, and
Platecarpus ictericus is the most commonly occurring species. There is some controversy regarding the description of the genus Platecarpus since it includes some diverse, and possibly unrelated forms.

The type specimen of Platecarpus (P. planiforms) was discovered by Professor B. F. Mudge and was classified by Edward Drinker Cope as Clidastes planiformes. In 1898, on further analysis of the remains, it was determined that the mosasaur be placed in a separate genus, Platecarpus. The type specimen underwent another taxonomic review in 1967, when paleontologist Dale Russell determined that the remains were too fragmentary to be placed within any genus, and deemed it to be a specimen of "uncertain taxonomic position". A 2006 discovery in the Smoky Hill Chalk of Kansas re-affirmed this position with the discovery a complete fossilized skull being unearthed.

Monday, October 4, 2010

October 4, 2010 : Aspidochelone (Myth)


According to the tradition of the Physiologus and medieval bestiaries, the aspidochelone is a fabled sea creature, variously described as a large whale or sea turtle, that is as large as an island. The name aspidochelone appears to be a compound word combining Greek aspis (which means either "asp" or "shield"), and chelone, the turtle. It rises to the surface from the depths of the sea, and entices unwitting sailors to make landfall on its huge shell. In Old English literature, in the poem The Whale, the creature appears under the name Fastitocalon, apparently a variant of aspidochelone. In the moralistic allegory of the Physiologus and bestiary tradition, the aspidochelone represents Satan, who deceives those whom he seeks to devour. 

One version of the Latin text of the Physiologus reads:

"There is a monster in the sea which in Greek is called aspidochelone, in Latin "asp-turtle"; it is a great whale, that has what appear to be beaches on its hide, like those from the sea-shore. This creature raises its back above the waves of the sea, so that sailors believe that it is just an island, so that when they see it, it appears to them to be a sandy beach such as is common along the sea-shore. Believing it to be an island, they beach their ship alongside it, and disembarking, they plant stakes and tie up the ships. Then, in order to cook a meal after this work, they make fires on the sand as if on land. But when the monster feels the heat of these fires, it immediately submerges into the water, and pulls the ship into the depths of the sea."

"Such is the fate of all who pay no heed to the Devil and his wiles, and place their hopes in him: tied to him by their works, they are submerged into the burning fire of Gehenna: for such is his guile."

Posts during October will be of real-life sea monsters, long extinct, as well as those of myth and folklore.

Sunday, October 3, 2010

October 3, 2010 : Scylla (Myth)


In Greek mythology, Scylla (pronounced /ˈsɪlə/, sil-uh; Greek: Σκύλλα, Skulla) was a monster that lived on one side of a narrow channel of water, opposite its counterpart Charybdis. The two sides of the strait were within an arrow's range of each other—so close that sailors attempting to avoid Charybdis would pass too close to Scylla and vice versa.

Scylla was a horrible sea monster with six long necks equipped with grisly heads, each of which contained three rows of sharp teeth. Her body consisted of twelve tentacle-like legs and a cat's tail and with four to six dog-heads ringing her waist. She was one of the children of Phorcys and either Hecate, Crataeis, Lamia or Ceto (all of whom may be various names for the same goddess. Some sources, including Stesichorus, cite her parents as Triton and Lamia.

Traditionally the strait has been associated with the Strait of Messina between Italy and Sicily, but more recently this theory has been challenged, and the alternative location of Cape Scilla in northwest Greece has been suggested by Tim Severin.

The phrase "between Scylla and Charybdis" (popularly reworded "between a rock and a hard place") has come to mean being in a state where one is between two dangers and moving away from one will cause you to be in danger from the other.

Posts during October will be of real-life sea monsters, long extinct, as well as those of myth and folklore.

Saturday, October 2, 2010

October 2, 2010 : Charybdis (Myth)


In Greek mythology, Charybdis or Kharybdis (pronounced /kəˈrɪbdɨs/; in Greek, Χάρυβδις) was a sea monster, once a beautiful naiad and the daughter of Poseidon and Gaia. She takes form as a huge bladder of a creature whose face was all mouth and whose arms and legs were flippers and who swallows huge amounts of water three times a day before belching them back out again, creating whirlpools. In some variations of the tale, Charybdis is just a large whirlpool rather than a sea monster. Charybdis was very loyal to her father in his endless feud with Zeus; it was she who rode the hungry tides after Poseidon had stirred up a storm, and led them onto the beaches, gobbling up whole villages, submerging fields, drowning forests, claiming them for the sea. She won so much land for her father's kingdom that Zeus became enraged and changed her into a monster.

The myth has Charybdis lying on one side of a blue, narrow channel of water. On the other side of the strait was Scylla, another sea-monster. The two sides of the strait are within an arrow's range of each other, so close that sailors attempting to avoid Charybdis will pass too close to Scylla and vice versa. The phrase "between Scylla and Charybdis" has come to mean being in a state where one is between two dangers and moving away from one will cause you to come closer to the other. "Between Scylla and Charybdis" is the origin of the phrase "between the rock and the whirlpool" (the rock upon which Scylla dwelt and the whirlpool of Charybdis) and may also be the genesis of the phrase "between a rock and a hard place".

According to Thomas Bulfinch, based on writings of Homer, Charybdis stole the oxen of Geryon from Hermes, in whose possession they had been at the time, and was transformed into a sea monster as a punishment.

The phrase "between Scylla and Charybdis" (popularly reworded "between a rock and a hard place") has come to mean being in a state where one is between two dangers and moving away from one will cause you to be in danger from the other.

Posts during October will be of real-life sea monsters, long extinct, as well as those of myth and folklore.

Friday, October 1, 2010

October 1, 2010 : Pliosaur (Extinct)


Pliosaurs were marine reptiles from the Jurassic and Cretaceous Periods. The pliosaurs, along with their relatives, the true plesiosaurs, and other members of Sauropterygia, were not dinosaurs. They originally included only members of the family Pliosauridae, of the Order Plesiosauria, but several other genera and families are now also included, the number and details of which vary according to the classification used.

The group was characterised by having a short neck and an elongated head, in contrast to the long-necked plesiosaurs. They were carnivorous and their long and powerful jaws carried many sharp, conical teeth. Pliosaurs range from 4 to 15 metres and more in length. Their prey may have included fish, ichthyosaurs and other plesiosaurs.

Typical genera include Kronosaurus, Liopleurodon, Pliosaurus and Peloneustes. Fossil specimens have been found in England, Mexico, South America, Australia and the Arctic region near Norway.

Many very early (from the Rhaetian (Latest Triassic) and Early Jurassic) primitive pliosaurs were very like plesiosaurs in appearance and indeed used to be included in the family Plesiosauridae.

The name "pliosaur" is derived from Greek, πλειων meaning "more/a higher degree" and σαυρος meaning "lizard". It is adapted from the name of the genus Pliosaurus, which means "more saurian", and was coined in 1841 by Richard Owen, who believed that pliosaurs represented a link between plesiosaurs and crocodilians (considered a type of "saurian"), particularly due to their crocodile-like teeth. Therefore, he named these animals to indicate that they were "more saurian" than the plesiosaurs.

The discovery of a very large pliosaur was announced in 2002, from Mexico. This pliosaur came to be known as the "Monster of Aramberri". The size of this specimen has been estimated to be about 15 metres (49 ft) long and it had a 3-metre (10 ft) long skull. Consequently, although widely reported as such, it does not belong to the genus Liopleurodon. The remains of this animal, consisting of a partial vertebral column, were dated to the Kimmeridgian of the La Caja Formation. The fossils were found much earlier, in 1985, by a geology student and were at first erroneously attributed to a theropod dinosaur by Hahnel. The remains originally contained part of a rostrum with teeth (now lost).

In August 2006, palaeontologists of the University of Oslo discovered the first remains of a pliosaur on Norwegian soil. The remains were described as "very well preserved as well as being unique in their completeness" and are the first complete skeleton of a pliosaur ever discovered. Whether it belongs to the genus Pliosaurus or Liopleurodon awaits publication of the fossil description. In the summer of 2008, the fossil remains of the huge pliosaur were dug up from the permafrost on Svalbard, a Norwegian island close to the North Pole. The excavation of the find is documented in the 2009 History television special Predator X.

On 26 October 2009 palaeontologists reported the discovery of potentially the largest pliosaur yet found. The fossil had a skull length of 2.4 metres (7 ft 10 in) and a body length of 16 metres (52 ft). Palaeontologist Richard Forrest told the BBC: "I had heard rumours that something big was turning up. But seeing this thing in the flesh, so to speak, is just jaw dropping. It is simply enormous."

The phrase "between Scylla and Charybdis" (popularly reworded "between a rock and a hard place") has come to mean being in a state where one is between two dangers and moving away from one will cause you to be in danger from the other.

Posts during October will be of real-life sea monsters, long extinct, as well as those of myth and folklore.