DOI: 10.5061/dryad.tk06g
title: Data from: An ecomorphospace for the Ammonoidea

description: The fossil conchs of ammonoids provide valuable information about the life
 habits of this extinct group. A new conch measurement, the apertural
 surface area, is introduced here along with modelled sizes of the buccal
 mass and the hyponome, based on ratios of these organs in comparison with
 the aperture height from the Recent Nautilus pompilius. A principal
 components analysis was performed using the three main characters (1)
 apertural surface area index (i.e., the ratio of the apertural surface and
 the conch diameter), (2) buccal mass area index (i.e., the ratio between
 the buccal mass area and the apertural surface area) and (3) coiling rate
 of the conch and reveals an ecomorphospace where life history traits can
 be tentatively assigned to species of the Ammonoidea. In this morphospace,
 Recent Nautilus has a marginal position, being one of the ectocochleate
 cephalopods with best properties for active life (capacity for handling
 large food items, rather good mobility). In contrast, most ammonoids
 possessed, at comparable conch sizes, much smaller buccal apparatuses and
 hyponomes, suggesting a more passive life history with reduced mobility
 potential and reduced capacities for larger prey items.
description: Species
 listList of species
 investigated. MB.C. = Museum für Naturkunde, BerlinSupplementary Table
 1.xlsxOntogenetic
 dataList of the conch
 parameters, whorl expansion rate (WER), apertural surface area index
 (ASAI) and buccal mass area index (BMAI) for all half whorl measurements
 for each specimen and their PCA values.Supplementary Table
 2.xlsxSupplementary Fig
 1Simple dm/ASarea plot to
 outline the position of the various studied cross sections. The nine
 specimens divide into three groups: 1) Forms with a high ASA (*Nautilus*,
 *Macrocephalites* and in the adult stage *Hammatocyclus*), 2) Forms with a
 moderate ASA (*Revilloceras* and *Joannites*, *Metalegoceras* in the adult
 stage) and 3) Forms with low ASA (*Choffatia* and
 *Sageceras*).Supplementary Fig
 2Simple ASarea/BMAI plot
 to outline the position of the various studied cross sections. In the nine
 highlighted specimens, it is clear to see that for a given ASA there can
 be a range of BMAIs. The disparity in BMAI increases from the hatchling
 stage through to the adults. In the subadult/adult stages, some specimens
 possess relatively small buccal apparatus (*Revilloceras* and *Joannites*)
 restricting them to smaller food items whereas other specimens were
 capable of eating larger prey (*Nautilus*,
 *Sageceras*).Supplementary Fig
 3Simple WER/ASAI plot to
 outline the position of the various studied cross sections. The blue lines
 indicate the relationship between the ASAI and WER for simple geometric
 apertural shapes, the three lines from the top represent depressed
 ellipsoids of decreasing intensity, the fourth line a circle and the
 bottom two lines compressed ellipsoids.Supplementary Fig
 4Ontogenetic trajectories
 of the conch width index, umbilical width index and whorl expansion rate,
 as well as the two new parameters, apertural surface area index and buccal
 mass area index, of three ammonoid species: A – *Hammatocyclus pollex*
 Ebbighausen, Korn & Bockwinkel, 2010, specimen MB.C.18601.7 (Early
 Carboniferous, Gourara, Algeria), B – *R**evilloceras granofalcatum
 *(Kullmann, 1961), specimen MB.C.9090.1 (Early Carboniferous, Anti-Atlas,
 Morocco) and C – *Metalegoceras sundaicum* (Haniel, 1915), specimen MNHN
 Paris 1925-16 B7532 (Early Permian, Timor)*.*Supplementary Fig
 5Ontogenetic trajectories
 of the conch width index, umbilical width index and whorl expansion rate,
 as well as the two new parameters, apertural surface area index and buccal
 mass area index, of three ammonoid species: A – *J**oannites cymbiformis
 *(Wulfen, 1793), specimen MB.C.6352.2 (Late Triassic, Austria), B –
 *Sageceras haidingeri* (Hauer, 1849), specimen MB.C.6008.4 (Late Triassic,
 Austria) and C – *Tropites subbullatus *(Hauer, 1849), specimen MB.C.7724
 (Late Triassic, Austria).Supplementary Fig
 6Ontogenetic trajectories
 of the conch width index, umbilical width index and whorl expansion rate,
 as well as the two new parameters, apertural surface area index and buccal
 mass area index, of two ammonoid species and a *Nautilus* species: A –
 *Macrocephalites macrocephalus *(Schlotheim, 1813), specimen MB.C.26518
 (Middle Jurassic, Westphalia), B – *Choffatia isabellae* Bonnot et al.,
 2008, specimen MB.C.26550 (Middle Jurassic, Normandy) and C – *Nautilus
 pompilius* Linnaeus, 1758, specimen GPI Tübingen
 1431-K1.