Microstructural Adaptations for Abrasion Resistance and Fracture Control in Molluscan Shells

Belyea, P. R.; Carter, Joseph G.

doi:10.1029/sc005p0331

Cited by 1 publication

(4 citation statements)

References 0 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Homogenous microstructure is composed of aragonite granules with highly ordered crystallographic orientation but little physical organization (Bøggild 1930; Bandel 1979, 1990; Carter and Clark 1985; Chateigner et al 2000; Avery and Etter 2006). The lack of physical organization of homogenous granules and limited organic matrix is less metabolically expensive than construction of other highly ordered microstructural types (Taylor and Layman 1972; Palmer 1981, 1983, 1992; Belyea and Carter 1990; Avery and Etter 2006). Prismatic microstructure is composed of parallel first-order prisms (Bandel 1979, 1990; Carter and Clark 1985).…”

Section: Resultsmentioning

confidence: 99%

“…Both Pseudolividae species use multiple (10+) layers of weakly ordered fibrous CL in their shell-wall and callus construction, but S. santander uses more poorly ordered homogenous and irregularly ordered fibrous material to construct an EPC. These poorly organized microstructures require less metabolic energy for deposition, possibly allowing for more rapid shell construction (Taylor and Layman 1972; Palmer 1981, 1983, 1992; Belyea and Carter 1990; Avery and Etter 2006). The presence of a siliciclastic grain within the shell wall (Fig.…”

Section: Discussionmentioning

confidence: 99%

“…The “plywood”-like nature of CL, with its frequent changes in the direction of first-order lamellae and second-order lathes, redirects propagating cracks, resulting in a loss of energy when bridging between layers (Cook and Gordon 1964; Currey and Kohn 1976; Currey 1977; Kamat et al 2000; Avery and Etter 2006; Salinas and Kisailus 2013). Homogenous microstructure has been shown to be resistant to mechanical abrasion, and is therefore cited as a possible defense against drilling predation, but is inferior at preventing crack propagation (Gabriel 1981; Belyea and Carter 1990; Avery and Etter 2006). The location of the EPC on the ventral surface of the animal suggests the EPC is not a drilling predation deterrent.…”

Section: Discussionmentioning

confidence: 99%

“…Thickening the shell in any way would provide added strength (Currey and Kohn 1976; West and Cohen 1996; Avery and Etter 2006), and possessing more shell layers, even of poorly organized microstructure would provide additional crushing resistance (Currey 1988; West and Cohen 1996; Avery and Etter 2006). The limited organic matrix, and therefore less metabolically expensive microstructure, could allow for rapid deposition of shell layers (Taylor and Layman 1972; Palmer 1981, 1983, 1992; Currey 1988; Belyea and Carter 1990; Avery and Etter 2006). Our observation of anomalous shell-wall growth associated with EPC development suggests there is a connection in the underlying genetic program that allows for the rapid evolution of the EPC and also results in reduced organic matrix in shell development.…”

Section: Discussionmentioning

confidence: 99%

See 3 more Smart Citations

Convergence, parallelism, and function of extreme parietal callus in diverse groups of Cenozoic Gastropoda

et al. 2020

View full text Add to dashboard Cite

We use scanning electron microscopy imaging to examine the shell microstructure of fossil and living species in five families of caenogastropods (Strombidae, Volutidae, Olividae, Pseudolividae, and Ancillariidae) to determine whether parallel or convergent evolution is responsible for the development of a unique caenogastropod trait, the extreme parietal callus (EPC). The EPC is defined as a substantial thickening of both the spire callus and the callus on the ventral shell surface such that it covers 50% or more of the surface. Caenogastropods as a whole construct the EPC convergently, using a variety of low-density, poorly organized microstructures that are otherwise uncommon in caenogastropod non-callus shell construction. Within clades, however, we see evidence for parallelism in decreased regulation in both the shell and callus microstructure. Low-density and poorly ordered microstructure—such as used for the EPC—uses less organic scaffolding and is less energetically expensive than normal shell microstructure. This suggests the EPC functions to rapidly and inexpensively increase shell thickness and overall body size. Tests of functional ecology suggest that the EPC might function both to defend against crushing predation through increased body size and dissipation of forces while aiding in shell orientation of highly mobile gastropods. These interpretations hinge on the current phylogenetic placement of caenogastropod families, emphasizing the essential contribution of phylogeny when interpreting homoplasy.

show abstract