Quantitative estimates of visual performance features in fossil birds

Schmitz, Lars

doi:10.1002/jmor.10720

Cited by 34 publications

(53 citation statements)

References 52 publications

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“…Larger sockets strongly correlate with larger eyes as shown by data on fish (SI Appendix, Estimating Eye and Pupil Size in Early Tetrapods and Fig. S4), reptiles (15), birds (16), and primates (17). Evidence spanning such a broad bracket of vertebrates shows that eye socket size in our group of ancient animals reliably captures what their eye size would have been.…”

Section: Computational Visual Ecologysupporting

confidence: 60%

Massive increase in visual range preceded the origin of terrestrial vertebrates

MacIver

Schmitz

Mugan

et al. 2017

Proc. Natl. Acad. Sci. U.S.A.

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The evolution of terrestrial vertebrates, starting around 385 million years ago, is an iconic moment in evolution that brings to mind images of fish transforming into four-legged animals. Here, we show that this radical change in body shape was preceded by an equally dramatic change in sensory abilities akin to transitioning from seeing over short distances in a dense fog to seeing over long distances on a clear day. Measurements of eye sockets and simulations of their evolution show that eyes nearly tripled in size just before vertebrates began living on land. Computational simulations of these animal's visual ecology show that for viewing objects through water, the increase in eye size provided a negligible increase in performance. However, when viewing objects through air, the increase in eye size provided a large increase in performance. The jump in eye size was, therefore, unlikely to have arisen for seeing through water and instead points to an unexpected hybrid of seeing through air while still primarily inhabiting water. Our results and several anatomical innovations arising at the same time suggest lifestyle similarity to crocodiles. The consequent combination of the increase in eye size and vision through air would have conferred a 1 million-fold increase in the amount of space within which objects could be seen. The "buena vista" hypothesis that our data suggest is that seeing opportunities from afar played a role in the subsequent evolution of fully terrestrial limbs as well as the emergence of elaborated action sequences through planning circuits in the nervous system. fish-tetrapod transition | vision | visual ecology | terrestriality | prospective cognition B efore terrestrial vertebrates arose, their ancestors inhabited underwater environments, where vision is highly compromised compared with vision above water. The visual difference between life in water and life above it is comparable with driving fast on a foggy road, where our responses must be rapid and simple, vs. driving in clear daylight conditions, where deliberation over more complex choices is enabled by the vast increase in sensory range. Nonetheless, although an immense quantity of work has been done on the emergence of limbs during the evolution of land vertebrates, how visual capability changed during the transition from water to land has not been explored. In part, this lack of exploration is because computational visual ecology-necessary to interpret the fossil data-has not been combined with early tetrapod paleontology. Through combining these disciplines, here we probe the evolutionary history of the switch in our visual sensory ecology from water to air. Surprisingly, our results show that eyes tripled in size just before full-time life on land evolved. Convergent lines of evidence, including our own, strongly support the hypothesis that a crocodilian ecotype-using the greatly enhanced visual capabilities conferred by vision through air to prey on the bounty of unexploited invertebrates that long preceded the vertebrates onto ...

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Section: Computational Visual Ecologysupporting

confidence: 60%

Massive increase in visual range preceded the origin of terrestrial vertebrates

MacIver

Schmitz

Mugan

et al. 2017

Proc. Natl. Acad. Sci. U.S.A.

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“…Hall et al state there was no osteological proxy for axial length, yet the external scleral-ring diameter is correlated with axial length (9). All osteological features in our analysis are optically relevant, facilitating functional interpretations of morphospace.…”

mentioning

confidence: 69%

Response to Comment on “Nocturnality in Dinosaurs Inferred from Scleral Ring and Orbit Morphology”

Schmitz

Motani

2011

Science

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Hall et al . claim that it is not yet possible to infer the diel activity patterns of fossil archosaurs with high confidence. We demonstrate here that this assertion is founded on unscreened data, untenable assumptions, and inappropriate methods. Our approach follows ecomorphological and phylogenetic principles in a probabilistic framework, resulting in statistically well-supported reconstructions of diel activity patterns in Mesozoic archosaurs.

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“…4). Previous work has shown that corneal diameter (Ritland, 1982;Hall and Ross, 2007), lens diameter (Schmitz, 2009), and the inner diameter of the sclerotic ring discriminate between nocturnal and diurnal birds (Hall, 2008b;Schmitz, 2008Schmitz, , 2009) and lizards (Hall, 2008a(Hall, , 2009. Nocturnal birds probably possess a larger inner diameter of the sclerotic ring and corneal diameter to allow more light to enter the eye (e.g., Martin, 1990).…”

Section: Type 1 Optic Foramen: Activity Pattern Analysesmentioning

confidence: 99%

“…Head length was measured to investigate the allometry of the optic foramen across birds, and was measured from the centerpoint of the junction of the keratinous sheath of the beak proper and the bony skull to the posterior-most point on the skull. Previous work has shown that both orbit diameter (Kay and Kirk, 2000;Ross, 2001, 2004;Kirk and Kay, 2004;Kirk, 2006a;Hall, 2008b) and the inner diameter of the sclerotic ring (Hall, 2008b;Schmitz, 2009) differ between nocturnal and diurnal species. Orbit diameter is a bony correlate of the transverse diameter of the eye, a useful indicator of overall eye size, and nocturnal birds exhibit a larger eye (Ritland, 1982;Hall and Ross, 2007) and orbit diameter than diurnal birds (Hall, 2008b).…”

Section: Measurementsmentioning

confidence: 99%

Optic Foramen Morphology and Activity Pattern in Birds

Hall

Iwaniuk

Gutiérrez-Ibáñez

2009

The Anatomical Record

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The optic nerve is the sole output of visual information from the ganglion cell layer of the retina to the brain in vertebrates. The size of the optic nerve is predicted to be closely associated with activity pattern, and, in many birds, the size of the optic foramen approximates the size of the optic nerve. Specifically, nocturnal species should have relatively smaller optic foramina than diurnal species because of differences in retinal pooling between activity patterns. If optic foramen morphology varies predictably with activity pattern in birds, this variable may be useful for interpreting activity pattern for birds that do not have soft tissue available for study, specifically for fossils. Across 177 families (from 27 orders), we describe four different optic foramen morphologies, only one of which corresponds well with the size of the optic nerve and is therefore appropriate for activity pattern analyses. Here, we test our hypothesis that nocturnal species will have relatively smaller optic foramina than diurnal species, across all species that we measured that have a discrete optic foramen. Regression analyses using species as independent data points and using comparative methods yielded significant differences in optic foramen size between nocturnal and diurnal species relative to three variables: head length, orbit depth, and sclerotic ring inner diameter. Nocturnal species consistently exhibit significantly smaller relative optic foramen diameters than diurnal species. Our results indicate that optic foramen diameter, in combination with either the sclerotic ring or the orbit diameter, can be used to predict activity pattern.

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Quantitative estimates of visual performance features in fossil birds

Cited by 34 publications

References 52 publications

Massive increase in visual range preceded the origin of terrestrial vertebrates

Massive increase in visual range preceded the origin of terrestrial vertebrates

Response to Comment on “Nocturnality in Dinosaurs Inferred from Scleral Ring and Orbit Morphology”

Optic Foramen Morphology and Activity Pattern in Birds

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