Shells T Travel 07 of 12
Ammonite
Dactylioceras commune
T at zero: every turn stays in one plane, so the shell is a flat coil.
- W widening
- 1.62
- D distance
- 0.5
- T travel
- 0
- S shape
- round
- turns
- 8.9
The settings our model uses to draw it, tuned by eye against photographs.
The real shell · about 65 mm
Its name means finger horn, after the ribs.
Ammonites lived for some 340 million years and died out with the dinosaurs.
- Lives
- Fossil, Lower Jurassic, about 180 million years ago; fine specimens from England and Germany
- In the exhibition
- Room 2, Four numbers: one of three shells for T, how far it slides.