X.—
            <b>The Mode of Life of Certain Goniatites</b>

Currie, Ethel D.

doi:10.1144/transglas.22.2.169

Cited by 6 publications

(7 citation statements)

References 10 publications

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“…It is concluded that the only effective way of accomplishing this was to have removed liquid from its camerae. Revised calculations on the densities of other ammonoids previously published by Trueman ( 1941) and Currie (1957) suggest that in all cases significant quantities of water would have been required in the camerae of these shells if they assumed neutral buoyancy. However, the reliability of the results of the calculations remains in doubt at present due to a lack of knowledge of the amount of shell material lost during diagenesis.…”

Section: Discussionmentioning

confidence: 98%

“…Buoyancy calculations on other ammonoids Trueman (1941) and Currie (1957) have obtained data on the shells of ammonites and goniatites; from these they calculate the densities of the animals in life. These calculations are now known to be inaccurate due to their using incorrect values for the density of soft tissues and the density of shell material.…”

Section: Buoyancy Control In Buchicevas Bilobatummentioning

confidence: 99%

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Buoyancy Control in Ammonoids

Heptonstall

1970

LET

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A specimen of Buchiceras bilobatum is shown to have been able to maintain neutral buoyancy in water despite the ever increasing weight of epifaunal oysters which it carried on its shell. It is deduced that before settlement of the oyster spat, the camerae of the ammonite contained several grammes of water and that this was slowly pumped out as the oysters grew. Revised calculations on the densities of other ammonoids suggest that the presence of large quantities of liquid in cephalopod camerae was a common occurrence. The significance of this liquid in the growth, mode of life, and evolution of ammonoids is discussed.

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Section: Discussionmentioning

confidence: 98%

Section: Buoyancy Control In Buchicevas Bilobatummentioning

confidence: 99%

Buoyancy Control in Ammonoids

Heptonstall

1970

LET

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“…Such models were published by Moseley (1838), Trueman (1941), and later by Currie (1957); the latter two models were corrected by Heptonstall (1970), Reyment (1958Reyment ( , 1973, Mutvei and Reyment (1973), Westermann (1977), Saunders and Shapiro (1986), Tsujita andWestermann (1998), Westermann (1998b), Kröger (2000) and the latest much more complex calculations were done by Kröger (2002), Hammer and Bucher (2006) and Longridge et al (2009).…”

Section: Historymentioning

confidence: 99%

“…1, p. 360 ff). Trueman's (1941) and Currie's (1957) data were reevaluated by Heptonstall (1970) using modern estimates for cephalopod tissue and shell densities. Mainly the equations of Raup and Chamberlain (1967) were applied to buoyancy calculations with additional corrections and extrapolations for different shell parameters such as ribs introduced by Kröger (2002).…”

Section: Buoyancy Calculations For Ammonoidsmentioning

confidence: 99%

Ammonoid Buoyancy

Hoffmann

Lemanis

Naglik

et al. 2015

Topics in Geobiology

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“…Trueman (1941) noted that his equation and those of Moseley assume that the cross-section of the cone changes in a uniform manner, which is a deviation from true ammonite growth patterns. Heptonstall (1970) revised an oversight in Trueman’s equations and then calculated ammonite densities by using more accurate cephalopod shell densities (Trueman used the density of pure aragonite for the density of the shell, which led to notable error in the buoyancy calculations of both Trueman (1941) and Currie (1957). Further quantitative study of the volumetrics of the shell through mathematical methods and implications for the life habits of extinct ammonoids and nautiloids were the topics of numerous publications in the following decades; for comprehensive discussions of this topic, see Westermann (1996, 1999), Jacobs and Chamberlain (1996), Westermann and Tsujita (1999), and Ritterbush et al (2014).…”

Section: Introductionmentioning

confidence: 99%

A new approach using high-resolution computed tomography to test the buoyant properties of chambered cephalopod shells

Lemanis¹,

Zachow²,

Fußeis³

et al. 2015

Paleobiology

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The chambered shell of modern cephalopods functions as a buoyancy apparatus, allowing the animal to enter the water column without expending a large amount of energy to overcome its own weight. Indeed, the chambered shell is largely considered a key adaptation that allowed the earliest cephalopods to leave the ocean floor and enter the water column. It has been argued by some, however, that the iconic chambered shell of Paleozoic and Mesozoic ammonoids did not provide a sufficiently buoyant force to compensate for the weight of the entire animal, thus restricting ammonoids to a largely benthic lifestyle reminiscent of some octopods. Here we develop a technique using high-resolution computed tomography to quantify the buoyant properties of chambered shells without reducing the shell to ideal spirals or eliminating inherent biological variability by using mathematical models that characterize past work in this area. This technique has been tested onNautilus pompiliusand is now extended to the extant deep-sea squidSpirula spirulaand the Jurassic ammoniteCadocerassp. hatchling.Cadocerasis found to have possessed near-neutral to positive buoyancy if hatched when the shell possessed between three and five chambers. However, we show that the animal could also overcome degrees of negative buoyancy through swimming, similar to the paralarvae of modern squids. These calculations challenge past inferences of benthic life habits based solely on calculations of negative buoyancy. The calculated buoyancy ofCadocerassupports the possibility of planktonic dispersal of ammonite hatchlings. This information is essential to understanding ammonoid ecology as well as biotic interactions and has implications for the interpretation of geochemical data gained from the isotopic analysis of the shell.

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X.— The Mode of Life of Certain Goniatites

Cited by 6 publications

References 10 publications

Buoyancy Control in Ammonoids

Buoyancy Control in Ammonoids

Ammonoid Buoyancy

A new approach using high-resolution computed tomography to test the buoyant properties of chambered cephalopod shells

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