Bivalves
Bivalves means "two shells" (known as Valves); they are easily mistaken for Brachiopods or other Molluscs.
Aviculopecten
UPPER DEVONIAN TO UPPER PERMIAN. 360-260 MYA.
Aviculopecten are recognised by their unique wavy color streak on the shell.
15 cm is a decent size for an Aviculopecten.
It has equal spacing and ridges and a brown zig-zag pattern across the shell; we may never know why this pattern was here. It has a symmetrical shell.
Do you have an image of Aviculopecten?
Contact us at: fossilidentification@gmail.com
15 cm is a decent size for an Aviculopecten.
It has equal spacing and ridges and a brown zig-zag pattern across the shell; we may never know why this pattern was here. It has a symmetrical shell.
Do you have an image of Aviculopecten?
Contact us at: fossilidentification@gmail.com
Exogyra
LOWER TRIASSIC TO UPPER TERTIARY. 245-0 MYA.
Exogyra are recognised by their unique mother of pearl shell. In the modern world we call these Oysters.
17 cm is a decent size for an Exogyra.
Some have ridges and very distinctive growth lines. It is the only Bivalve fossil preserved with mother of pearl. It isn't always symmetrical.
17 cm is a decent size for an Exogyra.
Some have ridges and very distinctive growth lines. It is the only Bivalve fossil preserved with mother of pearl. It isn't always symmetrical.
Gryphaea
UPPER TRIASSIC TO UPPER JURASSIC. 22-140 MYA.
Gryphaea are recognised by their unique strange Ammonoid-like shell.
10 cm is a decent size for a Gryphaea.
In the Victorian era, Gryphaea was nicknamed 'The Devils toenail' because back then, that was the only reasonable explanation.
It looks like a Gastropod as it is coiled; it's growth lines
and spacing is random. An unusal feature is the Umbo
curls round to the Aperture. It has a symmetrical shell.
10 cm is a decent size for a Gryphaea.
In the Victorian era, Gryphaea was nicknamed 'The Devils toenail' because back then, that was the only reasonable explanation.
It looks like a Gastropod as it is coiled; it's growth lines
and spacing is random. An unusal feature is the Umbo
curls round to the Aperture. It has a symmetrical shell.
Inoceramus
UPPER CRETACEOUS. 90-85 MYA.
Inoceramus are recognised by their unique asemetrical semicircle shell.
20 cm is a decent size for an Inoceramus.
It has equal growth lines, no ridges, and an asymmetrical shell.
20 cm is a decent size for an Inoceramus.
It has equal growth lines, no ridges, and an asymmetrical shell.
Lopha
UPPER JURASSIC TO UPPER CRETACEOUS. 160-70 MYA.
Lopha are recognised by their unique Mammoth Tooth effect.
7 cm is a decent size for a Lopha.
It has very sharp ridges; growth lines are rarely visible (visible in image). It has an asymmetrical shell.
7 cm is a decent size for a Lopha.
It has very sharp ridges; growth lines are rarely visible (visible in image). It has an asymmetrical shell.
Modiolus
LOWER DEVONIAN TO UPPER TERTIARY. 400-0 MYA.
Modiolus are recognised by their unique approximate 90 degree turn in the ridges.
20 cm is a decent size for a Modiolus.
It has equal spacing and growth lines, that follow approximately 90 degrees around the Umbo; it has no ridges. It has an asymmetrical shell.
(This image shows Modiolus with a Crinoid segment and long dent on the shell! This description refers to the Modiolus only, not the Crinoid segment or long dent!)
20 cm is a decent size for a Modiolus.
It has equal spacing and growth lines, that follow approximately 90 degrees around the Umbo; it has no ridges. It has an asymmetrical shell.
(This image shows Modiolus with a Crinoid segment and long dent on the shell! This description refers to the Modiolus only, not the Crinoid segment or long dent!)
Myophorella
LOWER JURASSIC TO LOWER JURASSIC. 190-130 MYA.
Myophorella are recognised by their unique spine-covered shell.
5 cm is a decent size for a Myophorella.
It has spines in diagonal rows; the spines meet the ridge at an angle then go out from the ridge at the same angle.
It has one ridge and the growth lines aren't always visible.
It has an asymmetrical shell.
5 cm is a decent size for a Myophorella.
It has spines in diagonal rows; the spines meet the ridge at an angle then go out from the ridge at the same angle.
It has one ridge and the growth lines aren't always visible.
It has an asymmetrical shell.
Neithea
LOWER CRETACEOUS TO UPPER CRETACEOUS. 130-70 MYA.
Neithea are recognised by their unique Heptagonal shell.
10 cm is a decent size for a Neithea.
It has a Heptagonal shaped shell (counting every third large ridge and the Umbo). It's growth lines aren't usually visible.
It's spacing and ridge pattern shows one large ridge followed by two small ridges; this repeats consistently. Ridges decrease in size towards the Umbo. It has a symmetrical shell.
10 cm is a decent size for a Neithea.
It has a Heptagonal shaped shell (counting every third large ridge and the Umbo). It's growth lines aren't usually visible.
It's spacing and ridge pattern shows one large ridge followed by two small ridges; this repeats consistently. Ridges decrease in size towards the Umbo. It has a symmetrical shell.
Pholadomya
UPPER TRIASSIC TO TERTIARY. 220-0 MYA.
Pholadomya are recognised by their unique perfectly spaced growth lines.
10 cm is a decent size for a Pholadomya.
It has equal spacing and growth lines; it has no ridges.
It has an asymmetrical shell.
10 cm is a decent size for a Pholadomya.
It has equal spacing and growth lines; it has no ridges.
It has an asymmetrical shell.
Plagiostoma
UPPER TRIASSIC TO UPPER CRETACEOUS. 230-68 MYA.
Plagiostoma are recognised by their unique overlapping growth lines.
10 cm is a decent size for a Plagiostoma.
It has no ridges; it has equally spaced growth lines.
It has an asymmetrical shell.
Do you have an image of Plagiostoma?
Contact us at: fossilidentification@gmail.com
10 cm is a decent size for a Plagiostoma.
It has no ridges; it has equally spaced growth lines.
It has an asymmetrical shell.
Do you have an image of Plagiostoma?
Contact us at: fossilidentification@gmail.com
Sphenoceramus
UPPER CRETACEOUS. 90-85 MYA.
Sphenoceramus are recognised by their unique overlapping growth lines and ridges creating a Rugose coral effect.
10 cm is a decent size for a Sphenoceramus.
It has a very rounded shell; it has equal spacing and ridges; it's growth lines, when overlapping the ridges, creates a bump and the space disappears. It has a symmetrical shell.
Do you have an image of Sphenoceramus?
Contact us at: fossilidentification@gmail.com
10 cm is a decent size for a Sphenoceramus.
It has a very rounded shell; it has equal spacing and ridges; it's growth lines, when overlapping the ridges, creates a bump and the space disappears. It has a symmetrical shell.
Do you have an image of Sphenoceramus?
Contact us at: fossilidentification@gmail.com
Spondylus
LOWER JURASSIC TO UPPER TERTIARY. 190-0 MYA.
Spondylus are recognised by their unique Spines that give an extending effect to the ridges.
4 cm is a decent size for a Spondylus.
It has Spines around it's mouth; Growth lines are microsopic and are present but barely visible. It has equally spaced ridges; the pattern is basically large and small ridges alternating.
It has a symmetrical shell.
4 cm is a decent size for a Spondylus.
It has Spines around it's mouth; Growth lines are microsopic and are present but barely visible. It has equally spaced ridges; the pattern is basically large and small ridges alternating.
It has a symmetrical shell.
Streblopteria
MIDDLE MISSISSIPPIAN TO UPPER PERMIAN. 350-260 MYA.
Streblopteria are recognised by their unique brown stripes in the spaces.
3 cm is a decent size for a Streblopteria.
It has very subtle ridges, the spaces are brown; growth lines are not always visible. It has a symmetrical shell.
Do you have an image of Streblopteria?
Contact us at: fossilidentification@gmail.com
3 cm is a decent size for a Streblopteria.
It has very subtle ridges, the spaces are brown; growth lines are not always visible. It has a symmetrical shell.
Do you have an image of Streblopteria?
Contact us at: fossilidentification@gmail.com
Tellina
LOWER TERTIARY TO UPPER TERTIARY. 50-0 MYA.
Tellina are recognised by their unique subtle growth lines.
30 cm is a decent size for a Tellina.
It has no ridges but very distinctive growth lines.
It has a symmetrical shell.
30 cm is a decent size for a Tellina.
It has no ridges but very distinctive growth lines.
It has a symmetrical shell.
