Data on braininess in mammals, part 2

...continued from https://www.inaturalist.org/journal/milewski/95967-data-on-braininess-in-mammals-part-1#

Encephalisation quotients (as per Jerison), according to Wroe and Milne (2007, https://pubmed.ncbi.nlm.nih.gov/17492976/ and https://academic.oup.com/evolut/article/61/5/1251/6853918?login=false):

DASYURIDAE
Dasyurus geoffroii 0.66
Dasyurus maculatus 0.24
Dasyurus viverrinus 0.61
Sarcophilus harrissii 0.35
Thylacinus cynocephalus 0.45

THYLACOLEONIDAE
Thylacoleo carnifex 0.45

DIDELPHIDAE
Didelphis virginianus 0.17

MYRMECOBIIDAE
Myrmecobius fasciatus 0.59

PERAMELIDAE
Isoodon obesulus 0.31
Macrotis lagotis 0.51

CANIDAE
Canis dirus 1.17
Canis latrans 1.52
Canis lupus 1.24
Otocyon megalotis 1.13
Lupulella adusta 0.92
Lupulella mesomelas 1.19
Lycaon pictus 1.47
Vulpes chama 1.27

FELIDAE
Acinonyx jubatus 0.66
Caracal caracal 0.94
Panthera atrox 0.54
Panthera leo 0.66
Panthera pardus 0.76
Panthera onca 0.86
Panthera tigris 0.84

HYAENIDAE
Crocuta crocuta 1.04
Parahyaena brunnea 0.80
Proteles cristatus 0.91

MUSTELIDAE
Aonyx capensis1.24
Gulo gulo 1.33
Meles meles 0.91
Mellivora capensis 1.62

PROCYONIDAE
Procyon lotor 1.22

URSIDAE
Ursus americanus 1.02
Ursus arctos 0.72
Ursus maritimus 0.90
Ursus thibetanus 1.06

VIVERRIDAE
Arctictis binturong 0.57
Paradoxurus hermaphroditus 0.70
Viverricula indica 0.60

My commentary:

The mean encephalisation quotient for the above felids is 0.75. By contrast, that for canids is 1.24.

COZZI ET AL. 2014 (https://karger.com/bbe/article-abstract/83/1/9/326293/The-Brain-of-the-Horse-Weight-and-Cephalization)

Encephalisation quotients (as per Jerison), relative to that of Equus caballus:

EQUUS CABALLUS
0.78 according to Cozzi et al. (2014)
0.91 according to Shultz and Dunbar (2010, https://www.pnas.org/doi/abs/10.1073/pnas.1005246107):

Felis catus 1.0
Lynx lynx 0.85
Panthera leo 0.63
Panthera tigris 0.78

Canis lupus 0.74-1.55
Vulpes vulpes 0.90

Sus scrofa 0.60

Bos taurus 0.55
Capra hircus 0.71
Ovis aries 0.80

Camelus bactrianus 0.61

Loxodonta africana 1.67

Gorilla gorilla 1.76
Homo sapiens 6.62
Hylobates sp. 2.55
Macaca mulatta 1.86
Pan troglodytes 2.48

My commentary:

This study is disappointing despite its detail, because the allometric analysis is poor. Cozzi et al. (2014) obtained good original data on brain size in Equus caballus, but lack a firm grasp of allometry.

However, what this paper does nicely show is the convolution of the cerebrum in E. caballus. And apparently Equus quagga is even more extreme in the number of sulci on the brain. This convolution in equids seems to exceed that in Bos.

Braininess in Equus caballus is

• much greater than in Bos taurus,
• greater than in Camelus bactrianus and Sus scrofa, and
• similar to that in Capra hircus and Ovis aries.

Posted on 23 June, 2024 17:48 by milewski