AMMONITES
Ammonites are one of the most common, marine environment, Fossils of the Mesozoic Era.
People used to think that when Stephen and Matilda built Whitby Abbey, it was covered in snakes; they believed that all the snakes were turned to stone, but there was one problem; they had no Skull or head, so the Monks carved heads on them. A problem with that theory was that Ammonites were being found in other places (e.g: Lyme Regis, Oxford...etc). Of course we now know that they were creatures similar to the modern day Nautilus.
They are Squid-like creatures, like Belemnites. All that remains of these once dominant Ocean creatures are their shells, which they would have built themselves and lived inside.
Amaltheus
LOWER JURASSIC. 190-185 MYA.
Amaltheus is recognised by it's unique curved ridges and spikes on the ridges. Like most Ammonites, it would have used jet propulsion to move around.
They only thrived in the early Jurassic oceans.
3 inches is a decent size for an Amaltheus.
The ridges are sharp, curved and the widths spaced like the ridges. It has spikes on ridges.
They only thrived in the early Jurassic oceans.
3 inches is a decent size for an Amaltheus.
The ridges are sharp, curved and the widths spaced like the ridges. It has spikes on ridges.
Austiniceras
LOWER CRETACEOUS. 70-95 MYA.
Austiniceras is recognised by it's unique flat shell. Like most Ammonites, it would have used jet propulsion to move around.
It only thrived in the late Cretaceous oceans.
3 meters is a decent size for an Austiniceras.
The ridges are small, not always clear and the widths spaced like the ridges.
It only thrived in the late Cretaceous oceans.
3 meters is a decent size for an Austiniceras.
The ridges are small, not always clear and the widths spaced like the ridges.
Caloceras
LOWER JURASSIC. 200-190 MYA.
Caloceras is recognised by it's closely ridged shell. Like most Ammonites, it would have used jet propulsion to move around.
It only thrived in the early Jurassic oceans.
10 inches is a decent size for a Caloceras.
It only thrived in the early Jurassic oceans.
10 inches is a decent size for a Caloceras.
Dactylioceras
LOWER JURASSIC. 200-170 MYA.
Dactylioceras is recognised by it's unique rectangular-shaped tubed shell and ridges split on the curves. Like most Ammonites, it would have used jet propulsion to move around.
It only thrived in the early Jurassic oceans.
2 inches is a decent size for Dactylioceras. The ridges are sharp and their width spaced out like the ridges. The ridges drop almost 90 degrees at the curves. The ridges split on all the curves.
It only thrived in the early Jurassic oceans.
2 inches is a decent size for Dactylioceras. The ridges are sharp and their width spaced out like the ridges. The ridges drop almost 90 degrees at the curves. The ridges split on all the curves.
Euhoplites
MIDDLE CRETACEOUS. 110-100 MYA.
Euhoplites is recognised by it's interesting pattern and joined ridges on the curves.
Like most Ammonites, it would have used jet propulsion to move around.
It only thrived in the middle Cretaceous oceans. 4 inches is a decent size.
Ridges and widths are spaced evenly.
The pattern of the ridges shows alternating half and full length ridges along the coiled tube.
Alternate ridges have spikes at both ends.
Like most Ammonites, it would have used jet propulsion to move around.
It only thrived in the middle Cretaceous oceans. 4 inches is a decent size.
Ridges and widths are spaced evenly.
The pattern of the ridges shows alternating half and full length ridges along the coiled tube.
Alternate ridges have spikes at both ends.
Hamites (also known as a 'Uncoiled Ammonite' or Polyptychoceras).
MIDDLE CRETACEOUS. 110-100 MYA.
Hamitites is recognised by it's unique part-uncoiled shell.
Unlike most Ammonites, it is not completely coiled.
Like most Ammonites, it would have used jet propulsion to move around, but blows water over it's shell to navigate.
It only thrived in the Cretaceous oceans.
5 inches is a decent size for a Hamitites.
The ridges are small and the spaces are in proportion with the width of the ridges.
Unlike most Ammonites, it is not completely coiled.
Like most Ammonites, it would have used jet propulsion to move around, but blows water over it's shell to navigate.
It only thrived in the Cretaceous oceans.
5 inches is a decent size for a Hamitites.
The ridges are small and the spaces are in proportion with the width of the ridges.
Hyphoplites
UPPER CRETACEOUS. 90-95 MYA.
Hyphoplites is recognised by it's unique expanding and curved ridges. Like most Ammonites, it would have used jet propulsion to move around.
It only thrived in the late Cretaceous oceans.
3 meters is a decent size for Hyphoplites.
The ridges are sharp and are spaced evenly in proportion with the width of ridges. Ridges curve and expand.
It only thrived in the late Cretaceous oceans.
3 meters is a decent size for Hyphoplites.
The ridges are sharp and are spaced evenly in proportion with the width of ridges. Ridges curve and expand.
Liparoceras
LOWER JURASSIC. 200-185 MYA.
Liparoceras is recognised by it's unique spikes on the ridges.
Like most Ammonites, it would have used jet propulsion to move around. It only thrived in the early Jurassic oceans.
5 inches is a decent size for Liparoceras.
The ridges are small and are spaced widely, with spikes.
Like most Ammonites, it would have used jet propulsion to move around. It only thrived in the early Jurassic oceans.
5 inches is a decent size for Liparoceras.
The ridges are small and are spaced widely, with spikes.
Lytoceras
LOWER JURASSIC TO UPPER CRETACEOUS. 200-70 MYA.
Lytoceras is recognised by it's unique large ridge every 10-5 small ones. Like most Ammonites, it would have used jet propulsion to move around.
8 inches is a decent size for Lytoceras.
The ridges are small and every 5-10 small ones, one big one occurs and the spaces are the same as the widths of the small ridges.
8 inches is a decent size for Lytoceras.
The ridges are small and every 5-10 small ones, one big one occurs and the spaces are the same as the widths of the small ridges.
Ludwigia
MIDDLE JURASSIC. 175-165 MYA.
Ludwigia is recognised by it's unique flat shell and curvy ridges. Like most Ammonites, it would have used jet propulsion to move around. 5 inches is a decent size for Ludwigia.
The ridges are small and spaces are wider than ridges. The ridges curve on the flat part of the shell.
The ridges are small and spaces are wider than ridges. The ridges curve on the flat part of the shell.
Macrocephalites
MIDDLE JURASSIC. 160-165 MYA.
Macrocephalites is recognised by it's unique split ridges. Like most Ammonites, it would have used jet propulsion to move around.
They grow extremely big, 3 meters is a decent size.
The ridges are sharp and are the same width as the ridges. The ridges split on the curves.
They grow extremely big, 3 meters is a decent size.
The ridges are sharp and are the same width as the ridges. The ridges split on the curves.
Macroscaphites (also known as 'uncoiled ammonite')
UPPER CRETACEOUS TO LATE CRETACEOUS. 130-70 MYA.
Macroscaphites is recognised by it's unique part-uncoiled shell. Unlike most Ammonites, it is not completely coiled. Like most Ammonites, it would have used jet propulsion to move around.
It only thrived in the Cretaceous oceans.
5 inches is a decent size for a Macroscaphites.
The ridges are small and the spaces are
the same width as the ridges.
It only thrived in the Cretaceous oceans.
5 inches is a decent size for a Macroscaphites.
The ridges are small and the spaces are
the same width as the ridges.
Phylloceras
UPPER TRIASSIC TO LOWER CRETACEOUS. 210-125 MYA.
Phylloceras is recognised by it's unique patten on the shell. It was one of the first ammonites. Like most Ammonites, it would have used jet propulsion to move around.
It was fairly common in the Jurassic and died out in the Cretaceous.
10 cm is a decent size for a Phylloceras.
The ridges are very small and well spaced.
It was fairly common in the Jurassic and died out in the Cretaceous.
10 cm is a decent size for a Phylloceras.
The ridges are very small and well spaced.
Psiloceras
LOWER JURASSIC. 206-200 MYA
Psiloceras is recognised by it's unique flat, wide shell. Like most Ammonites, it would have used jet propulsion to move around. It only thrived in the early JURASSIC oceans.
7 cm is a decent size for Psiloceras. Ridges are very small and are spaced near each other, sometimes not visibly preserved.
7 cm is a decent size for Psiloceras. Ridges are very small and are spaced near each other, sometimes not visibly preserved.
Stephanoceras
UPPER JURASSIC. 170-140 MYA.
Stephanoceras is recognised by it's unique split ridges at the curve.
Like most Ammonites, it would have used jet propulsion to move around.
It only thrived in the late Jurassic oceans.
4 inches is a decent size for Stephanoceras. The ridges are clear and spaced like waves.
The ridges are split on the curves.
Like most Ammonites, it would have used jet propulsion to move around.
It only thrived in the late Jurassic oceans.
4 inches is a decent size for Stephanoceras. The ridges are clear and spaced like waves.
The ridges are split on the curves.
