Picture: The mesocyon, the earliest tracked achestor of the wolves
ORIGIN OF THE WOLF
The earliest fossil carnivores that are certain to be the anchestor of today’s canids are the Eocene Miacids that lived 38-56 million years ago. There were two lines that evolved from the miacids – the feloidea (lions, cats, caracals) and the canoidea (wolves, dogs, foxes). The canoid line evolved from the Mesocyon that lived approximately 35 million years ago. It was the same size as today’s coyotes, and is believed to have lived in packs just like wolves do today. The line evolved further with (among others) the fox-like Leptocyon and the wolf-like Eukyon that wandered North America some 10 million years ago.
Baryonyx & Hypsilophodon, Miguel Ángel Amorín Fernández, 2013
The cool mud felt good between the little dinosaur’stoes. The pod came here to drink and nibble on weeds. They communed through pips and nods, confirming hierarchies and reinforcing connections. The muddy bank, the sound of the river, the emeralds and ceruleans of the forest all built layers of calm for the Hypsilophodonts. They were a nervous breed, but liked to be soothed.
A monitor whistled five quick notes, and the peace was gone. As the pod started to scamper, a Baryonyx shuffled from the green. Its long head swung slowly, obsidian eyes monitoring the frightened movement. Hypsilophodon, feet still in the cool mud, stood while the others panicked, watching the massive thing lumber through the hopping pod. It was big, silent—its motions methodical and confident; the pod was the opposite—small, squeaky, consumed by fear-born chaos. The Baryonyx looked towards the Hypsilophodon and the little dinosaur’s heart jumped. Within a second, it too had ducked into the woods, leaving behind only rustling leaves and footprints in the mud.
Euphanerops, a fossil jawless fish has been found to have paired anal fins. Previously paired fins were thought to be a trait only found in jawed fishes, but the paired anal fin of Euphanerops is particularly unique as jawed fishes have only been known to have unpaired anal fins. According to Dr. Samsom, "The unusual paired anal fin of Euphanerops lends support to the idea that there was some degree of developmental and evolutionary experimentation in some fish. After the Devonian period and the extinction of a lot of species, the jawed vertebrate body exhibits fewer deviations from the formula of paired pectoral, paired pelvic, unpaired dorsal and unpaired anal appendages. The discovery of new anatomical conditions will hopefully shed more light on the timing and sequence of the events underlying the origin and diversification of vertebrate appendages.”
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Opalised theropod dinosaur tooth, Lightning Ridge, New South Wales. Lightning Ridge in north-western New South Wales is a rich source of opals, and many beautiful and valuable opalised fossils have been found there. These opalised fossils date from the Cretaceous Period, with specimens coming from many animal groups including dinosaurs, marine reptiles, fish, early mammals and molluscs, as well as fossils of parts of plants.
Photo credit: © Carl Bento , Australian Museum
Let me introduce you to graptolites. These odd little prehistoric creatures were colonies of tiny marine animals which formed protective cup-like structures around their bodies and filter-fed on microscopic plankton. They’re classified as hemichordates, and their closest living relatives are a similar member of that group called pterobranchs.
They appeared in the fossil record between about 490 and 320 million years ago, and came in a wide range of shapes and sizes. There were single rows, double rows, branches, spirals, forks, and even net-like forms. The earliest types lived attached to the sea floor, but later ones floated around freely near the surface of the ocean and could reach lengths of up to 1.5m (~5ft). Some may have attached themselves to seaweed and floating debris, others are thought to have dangled from their own little bubble-like flotation rafts.
Their remains are so numerous and widespread that they’re very useful as “index fossils”, allowing paleontologists to precisely date the age of the rocks they’re found in.