iBet uBet web content aggregator. Adding the entire web to your favor.
iBet uBet web content aggregator. Adding the entire web to your favor.



Link to original content: https://pubmed.ncbi.nlm.nih.gov/28017610/
Bone Microvasculature Tracks Red Blood Cell Size Diminution in Triassic Mammal and Dinosaur Forerunners - PubMed Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
. 2017 Jan 9;27(1):48-54.
doi: 10.1016/j.cub.2016.10.012. Epub 2016 Dec 22.

Bone Microvasculature Tracks Red Blood Cell Size Diminution in Triassic Mammal and Dinosaur Forerunners

Adam K Huttenlocker  1 , C G Farmer  2
Affiliations
Free article

Bone Microvasculature Tracks Red Blood Cell Size Diminution in Triassic Mammal and Dinosaur Forerunners

Adam K Huttenlocker et al. Curr Biol. .
Free article

Abstract

Vertebrate red blood cells (RBCs) display a range of sizes, spanning orders of magnitude in volume in different clades [1]. The importance of this size variation to diffusion during exercise is reinforced by functional links between RBC and capillary diameters [2, 3]. Small RBCs, such as those of mammals (which lack nuclei) and birds, contribute to shorter diffusion distances and permit relatively fast O2 uptake kinetics [4]. Although constraints on RBC size have been tied to the cell's need to attend capillary sizes for effective gas diffusion [3], as well as to genome size evolution [5, 6], major questions persist concerning patterns of RBC size evolution and its paleobiological significance. Here, we evaluate the relationship between RBC sizes and bone histometry and use microstructural evidence to trace their evolution in a phylogeny of extinct tetrapods. We find that several fossilizable aspects of bone microstructure, including the sizes of vascular and lacunar (cellular) spaces, provide useful indicators of RBC size in tetrapods. We also show that Triassic non-mammalian cynodonts had reduced and densely packed vascular canals identical to those of some mammals and likely accommodated smaller, more mammal-like RBCs. Reduced channel diameters accommodating smaller RBCs predated the origin of crown mammals by as much as 70 million years. This discovery offers a new proxy for the physiologic status of the mammal and avian stem groups and contextualizes the independent origins of their increased activity metabolism.

Keywords: Archosauria; Synapsida; aerobic capacity; bone histology; erythrocyte.

PubMed Disclaimer

Similar articles

See all similar articles

Cited by

See all "Cited by" articles

LinkOut - more resources