Mammals
Against your impression, first true mammals had appeared in very early period of the evolutionary history of Vertebrate, the Triassic (about 200 million years ago).
"Mammalian evolution is a tale told by teeth mating to produce slightly altered descendant teeth.", a famous paleontologist S. J. Gould said, as a paleontological joke. It means: "The majority of fossil mammals are known only by their teeth."
Desmostylus hesperus (molar 1)
Desmostylus hesperus (molar 2)
Merycoidodon sp. (ancestral horse, lower jawbone)
Proterotherium sp. (ancestral horse, lower jawbone)
Shark tooth
Shark teeth are constantly replaced throughout their lifetime, we human cannot do that.
One shark sometimes spends over 30,000 teeth until the end of life, so fossilized shark teeth are easily found out.
Shark tooth
Worms in amber
Fossilized tree resin is called Amber, a kind of jewel. Ancient bugs and worms sometimes trapped in resin, turned into fossils together.
Their figures are mostly still alive. Please see the 30-million-year-ago-worms.
Ant
Myriapoda
Ammonites
They are a kind of marine animal, close relative of octopuses and squids. But unfortunately, they completely extincted 65 million years ago, so nowadays we can see them as fossils in the rocks.
They had Nautilus-like spiral shells that separated by some walls into chambers. Each chamber maybe contained some gases, so reserchers guess the animals were able to move up-and-down in the water.
partial fossil Baculites sp.
Muramotoceras yezoense
Cadoceras sp.
partial fossil Lamberticeras lamberti
Damesites damesi
Blastoids
One group of extincted echinoderms.
Like other echinoderms (starfishes, sea urchins etc.) , their main bodies ( = theca) were protected by a set of interlocking plates of calcium carbonate. The theca had a
stalk to attach the sea floor.
For more information, please see
our Scientific Column page, almost text are Japanese but you can see some illustrations and references.
Also, please visit our other page:
CT-scanned Echinodermata 3D Data Library.
Schizoblastus sp.
Pentremites sp.
Star Sand (Benthic foraminifera)
Star sands are one of the famous souvenir of southern Japanese islands. Against the name, they are not real sands but animal's shell, a species of benthic foraminifera,
Baculogypsina sphaerulata .
Most foraminiferas have microscopic scale, but fortunately, Star Sands are large enough to see with the naked eye. Although, enlarged movies are also beautiful.
Baculogypsina sphaerulata 1
Baculogypsina sphaerulata 2
Benthic foraminifera
Benthic foraminifera, a large group of unicellular organisms living on the bottom of water. They have calcium carbonate shells like molluscs.
Their fossils are used as an index of the past environment. Microfossils.
Cycloclypeus carpenteri
Uvigerina akitaensis
Calcarina sp.
Planktonic foraminifera
Also belonging to foraminifera group, floating in the water.
Their fossils are very common and found in large quantities, therefore used as a marker of rock's age, and as an index of past environmental changes. Microfossils.
Globigerina bulloides
Globigerina quinqueloba
Hirsutellla margaritae
Globigerinella aequilateralis
Globigerinoides sacculifer
Globoquadrina conglomerata
Menardella menardii
Globigerinoides fistulosus
Fohsella lobata
Radiolaria
A group of planktonic unicellular organisms, distinguished by their siliceous (glass) skeletons.
Their fossils are used as a marker of rock's age, and as an index of past environmental changes. Microfossils.
Spumellaria
Lychnocanoma sp.
Theocotylissa fimbria
Ostracoda
Very small multicelular organisms, mostly within 2-3 mm length, but they are relatives of shrimps and crabs.
They have two shells that made of calcium carbonate. Microfossils.
Hanaicythere sp.
Bairdioidea sp.
Robustaurila ishizakii
Cythere omotenipponica
Neonesidea sp.