A stunning example of an iridescent ammonite fossil of the species Psiloceras planorbis from North Somerset, UK.
The piece of limestone matrix measures 160 mm (6.3 inches) across and contains multiple very well preserved ammonite shells, the largest of which measures 78 mm, which is about as big as this species gets. The ammonites are perfectly preserved and have been prepared out of the rock to reveal the shells, which display some nice iridescent colours that change depending on the angle that the fossil is viewed at, with red and orange hues visible at certain viewing angles. The largest ammonite also has some very unusual encrusting serpulid worm casts on it. These worms encrusted shells that lay on the seafloor in the Jurassic and show what the ecosystem of the seafloor was like 200 million years ago. The fossil weighs 840 grams and has two cut flat bases and a rock-coloured plaster wedge on the back of the matrix to allow it to stand freely for display in multiple ways. A very impressive display fossil.
Around 200 million years old (Hettangian, Early Jurassic), this fossil would make a wonderful addition to any collection.