Project 4746: M. M. Yacobucci. 1999. Plasticity of Developmental Timing as the Underlying Cause of High Speciation Rates in Ammonoids. An example from the Cenomanian Western Interior Seaway of North America. Advancing Research on Living and Fossil Cephalopods. null:59-76.
Abstract
Rapid diversification of clades within a restricted geographic area is fairly common, and has been well studied as a model of adaptive radiation. The monophyletic clades produced by this type of event have been called “species flocks.” An investigation of the Cenomanian radiation of acanthoceratid ammonites in the North American Western Interior Seaway reveals that this clade shows all the characteristics of a species flock: the acanthoceratid genera are speciose and diversified rapidly, and many of the species are geographically restricted within the Western Interior, possibly due to environmental barriers. A cladistic analysis shows many true polytomies, a high autapomorphy to synapomor- phy ratio, and much parallelism, all reflecting rapid diversification from a single ancestral lineage. These ammonites also show pronounced plasticity of developmental timing. Most differences in morphology among taxa are due to small changes in developmental timing, and an unusually high number of progenic dwarf spinoff taxa occur in this clade, indicating that larger-scale changes in ontogenetic timing are also common. It seems, then, that the developmental program of this ammonite clade was exceedingly labile during its radiation. This plasticity may have allowed the clade to radiate so rapidly and profusely. As developmental plasticity may be a characteristic of ammonoids as a whole, this internal factor, rather than sensitivity to external environmental conditions, may be the root cause of high speciation rates in ammonoids.Read the article »
Article DOI: 10.1007/978-1-4615-4837-9_6
Project DOI: 10.7934/P4746, http://dx.doi.org/10.7934/P4746
This project contains | Matrices |
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Download Project SDD File | Total scored cells: 628 Total media associated with cells: 0 Total labels associated with cell media: 0 |
Characters | |
Total characters: 32 Total characters with associated media: 0 Total characters with media with labels: 0 Total character states: 135 Total character states with associated media: 0 Total character states with media with labels:0 Total unordered/ordered characters:32/0 |
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MorphoBank Project 4746
MorphoBank Project 4746
- Creation Date:
12 July 2023 - Publication Date:
12 July 2023 - Project views: 5190
- Matrix downloads: 4
Authors' Institutions
- Harvard University
Members
member name | taxa | specimens | media | chars | character
| cell scorings (scored, NPA, "-") | cell
| rules | ||||||
Brooke Long-Fox Project Administrator | 20 | 11 | 11 | 32 | 0 | 0 | 628 (628, 0, 0) | 0 | 0 | 0 |
Taxonomic Overview for Matrix 'M29356' (20 Taxa)
taxon | unscored cells |
scored cells |
no cell support |
NPA cells |
"-" cells | cell images | labels on cell images |
member access |
[1] † Forbesiceras Last Modified in 07/12/23 | 0 | 32 | 32 | 0 | 0 | 0 | 0 | 1 |
[2] † Lyelliceras Last Modified in 07/12/23 | 8 | 24 | 24 | 0 | 0 | 0 | 0 | 1 |
[3] † Neophlycticeras Last Modified in 07/12/23 | 0 | 32 | 32 | 0 | 0 | 0 | 0 | 1 |
[4] † Stoliczkaia Last Modified in 07/12/23 | 0 | 32 | 32 | 0 | 0 | 0 | 0 | 1 |
[5] † Acanthoceras Last Modified in 07/12/23 | 0 | 32 | 32 | 0 | 0 | 0 | 0 | 1 |
[6] † Acompsoceras Last Modified in 07/12/23 | 0 | 32 | 32 | 0 | 0 | 0 | 0 | 1 |
[7] † Calycoceras Last Modified in 07/12/23 | 0 | 32 | 32 | 0 | 0 | 0 | 0 | 1 |
[8] † Conlinoceras Last Modified in 07/12/23 | 0 | 32 | 32 | 0 | 0 | 0 | 0 | 1 |
[9] † Cunningtoniceras Last Modified in 07/12/23 | 2 | 30 | 30 | 0 | 0 | 0 | 0 | 1 |
[10] † Dunveganoceras Last Modified in 07/12/23 | 0 | 32 | 32 | 0 | 0 | 0 | 0 | 1 |
[11] † Graysonites Last Modified in 07/12/23 | 0 | 32 | 32 | 0 | 0 | 0 | 0 | 1 |
[12] † Mammites Last Modified in 07/12/23 | 0 | 32 | 32 | 0 | 0 | 0 | 0 | 1 |
[13] † Mantelliceras Last Modified in 07/12/23 | 0 | 32 | 32 | 0 | 0 | 0 | 0 | 1 |
[14] † Metoicoceras Last Modified in 07/12/23 | 0 | 32 | 32 | 0 | 0 | 0 | 0 | 1 |
[15] † Neocardioceras Last Modified in 07/12/23 | 1 | 31 | 31 | 0 | 0 | 0 | 0 | 1 |
[16] † Plesiacanthoceras Last Modified in 07/12/23 | 1 | 31 | 31 | 0 | 0 | 0 | 0 | 1 |
[17] † Plesiacanthoceratoides Last Modified in 07/12/23 | 0 | 32 | 32 | 0 | 0 | 0 | 0 | 1 |
[18] † Sharpeiceras Last Modified in 07/12/23 | 0 | 32 | 32 | 0 | 0 | 0 | 0 | 1 |
[19] † Spathites Last Modified in 07/12/23 | 0 | 32 | 32 | 0 | 0 | 0 | 0 | 1 |
[20] † Tarrantoceras Last Modified in 07/12/23 | 0 | 32 | 32 | 0 | 0 | 0 | 0 | 1 |
Project views
type | number of views | Individual items viewed (where applicable) |
Total project views | 5190 | |
Project overview | 215 | |
Matrix views | 176 | Matrix landing page (163 views); Matrix from Yacobucci 1999 (13 views); |
Taxon list | 1145 | |
Documents list | 149 | |
Specimen list | 1576 | |
Views for media list | 204 | |
Media views | 1611 | Media search (539 views); M890303 (98 views); M890304 (100 views); M890305 (106 views); M890306 (96 views); M890307 (96 views); M890308 (98 views); M890309 (98 views); M890310 (95 views); M890311 (96 views); M890312 (97 views); M890313 (92 views); |
Bibliography | 114 |
Project downloads
type | number of downloads | Individual items downloaded (where applicable) |
Total downloads from project | 4 | |
Matrix downloads | 4 | Matrix from Yacobucci 1999 (4 downloads); |