View source for Biology:Cephalic index

{{short description|Ratio of width to length of the head of an organism}}
[[File:Cephalic index.svg|thumb|Cephalic index viewed from above the head]]
The '''cephalic index''' or '''cranial index''' is a number obtained by taking the maximum width (biparietal diameter or BPD, side to side) of the head of an organism, multiplying it by 100 and then dividing it by their maximum length (occipitofrontal diameter or OFD, front to back). The index was once used to categorize human beings in the first half of the 20th century, but today it is used to categorize dogs and cats.

==Historic use in anthropology==
===Early anthropology===
[[File:Cephalic index map of Europe by Bertil Lundman, 1993.jpg|thumb|Cephalic index map of Europe by Bertil Lundman, 1993]]
The cephalic index was used by anthropologists in the early 20th century as a tool categorize human populations. It was used to describe an individual's appearance and for estimating the age of [[Biology:Fetus|fetus]]es for legal and obstetrical reasons.

The cephalic index was defined by Swedish professor of [[Biology:Anatomy|anatomy]] Anders Retzius (1796–1860) and first used in physical anthropology to classify ancient human remains found in Europe. The theory became closely associated with the development of racial anthropology in the 19th and early 20th centuries, when historians attempted to use ancient remains to model population movements in terms of racial categories. American anthropologist Carleton S. Coon also used the index in the 1960s, by which time it had been largely discredited.

[[File:PSM V59 D404 Cephalic indexes of skull shapes.png|thumb|Cephalic indexes of skull shapes. Long skull (left) – cephalic index 71.4; tall skull (center) – cephalic index 81; broad skull (right) – cephalic index 85]]

In the cephalic index model, human beings were characterized by having either a dolichocephalic (long-headed), mesaticephalic (moderate-headed), or brachycephalic (short-headed) cephalic index or cranial index.
[[File:Otmaa1917 1-1-.jpg|thumb|The children of the Tsar Nicholas II of Russia in June 1917, with loss of hair after fighting measles: among them, Tatiana had the skull with least cephalic index.]]

===Indices===
[[File:PSM V50 D602 World cephalic index map.jpg|thumb|1896 World cephalic index map]]
Cephalic indices are grouped as in the following table:

{| class="wikitable"
|-
! Females !! Males !! Scientific term !! Meaning !! Alternative term
|-
| < 75 || < 75.9  || ''dolichocephalic'' || 'long-headed' ||
|-
| 75 to 83 || 76 to 81 || ''mesaticephalic'' || 'medium-headed' || ''mesocephalic''; ''mesocranial''
|-
| > 83 || > 81.1 || ''brachycephalic'' || 'short-headed' || ''brachycranial''
|}

Technically, the measured factors are defined as the maximum width of the bones that surround the head above the [[Medicine:Temporal bone|supramastoid crest]] (behind the cheekbones), and the maximum length from the most easily noticed part of the glabella (between the eyebrows) to the most easily noticed point on the back part of the head.

===Controversy===

The usefulness of the cephalic index was questioned by Giuseppe Sergi, who argued that cranial morphology provided a better means to model racial ancestry.<ref>{{cite thesis| vauthors = Killgrove K |year=2005 |title=Bioarchaeology in the Roman World | degree = Masters | publisher = UNC Chapel Hill |url=http://www.piki.org/~kristina/Killgrove-2005-classics.pdf |archive-url=https://web.archive.org/web/20120328162246/http://www.piki.org/~kristina/Killgrove-2005-classics.pdf |archive-date=28 March 2012 |url-status=dead}}</ref> Also, Franz Boas studied the children of immigrants to the United States in 1910 to 1912, noting that the children's cephalic index differed significantly from their parents', implying that local environmental conditions had a significant effect on the development of head shape.<ref name="Holloway_2002">{{cite journal | vauthors = Holloway RL | title = Head to head with Boas: did he err on the plasticity of head form? | journal = Proceedings of the National Academy of Sciences of the United States of America | volume = 99 | issue = 23 | pages = 14622–3 | date = November 2002 | pmid = 12419854 | pmc = 137467 | doi = 10.1073/pnas.242622399 | bibcode = 2002PNAS...9914622H | doi-access = free }}</ref>

Boas argued that if craniofacial features were so malleable in a single generation, then the cephalic index was of little use for defining race and mapping ancestral populations. Scholars such as Earnest Hooton continued to argue that both environment and heredity were involved. Boas did not himself claim it was totally plastic.

In 2002, a paper by Sparks and Jantz re-evaluated some of Boas's original data using new statistical techniques and concluded that there was a "relatively high genetic component" of head shape.<ref>{{cite journal | vauthors = Sparks CS, Jantz RL | title = A reassessment of human cranial plasticity: Boas revisited | journal = Proceedings of the National Academy of Sciences of the United States of America | volume = 99 | issue = 23 | pages = 14636–14639 | date = November 2002 | pmid = 12374854 | pmc = 137471 | doi = 10.1073/pnas.222389599 | doi-access = free | bibcode = 2002PNAS...9914636S }}. See also the discussion in {{cite journal | vauthors = Holloway RL | title = Head to head with Boas: did he err on the plasticity of head form? | journal = Proceedings of the National Academy of Sciences of the United States of America | volume = 99 | issue = 23 | pages = 14622–14623 | date = November 2002 | pmid = 12419854 | pmc = 137467 | doi = 10.1073/pnas.242622399 | doi-access = free | bibcode = 2002PNAS...9914622H }}</ref> Ralph Holloway of Columbia University argues that the new research raises questions about whether the variations in skull shape have "adaptive meaning and whether, in fact, normalizing selection might be at work on the trait, where both extremes, hyperdolichocephaly and hyperbrachycephaly, are at a slight selective disadvantage."<ref name="Holloway_2002"/>

In 2003, anthropologists Clarence C. Gravlee, H. Russell Bernard, and William R. Leonard reanalyzed Boas's data and concluded that most of Boas's original findings were correct. Moreover, they applied new statistical, computer-assisted methods to Boas's data and discovered more evidence for cranial plasticity.<ref name=Gravlee>{{cite journal| vauthors = Gravlee CC, Bernard HR, Leonard WR |title=Heredity, environment, and cranial form: A reanalysis of Boas's immigrant data|journal=American Anthropologist|date=March 2003|volume=105|issue=1|pages=125–138|doi=10.1525/aa.2003.105.1.125|url=http://www.gravlee.org/files/pdfs/gravlee03a.pdf|access-date=2018-03-23|hdl=2027.42/65137|archive-url=https://web.archive.org/web/20140730140427/http://www.gravlee.org/files/pdfs/gravlee03a.pdf|archive-date=30 July 2014|url-status=dead|hdl-access=free}}</ref> In a later publication, Gravlee, Bernard and Leonard reviewed Sparks's and Jantz's analysis. They argue that Sparks and Jantz misrepresented Boas's claims, and that Sparks's and Jantz's data support Boas. For example, they point out that Sparks and Jantz look at changes in cranial size in relation to how long an individual has been in the United States in order to test the influence of the environment. Boas, however, looked at changes in cranial size in relation to how long the mother had been in the United States. They argue that Boas's method is more useful, because the prenatal environment is a crucial developmental factor.<ref name=Gravlee/>

Jantz and Sparks responded to Gravlee et al., reiterating that Boas' findings lacked biological meaning, and that the interpretation of Boas' results common in the literature was biologically inaccurate.<ref>{{cite journal | vauthors = Sparks CS, Jantz RL  |title=Changing Times, Changing Faces: Franz Boas's Immigrant Study in Modern Perspective |journal=American Anthropologist |volume=105 |issue=2 |year=2003 |pages=333–337 |doi=10.1525/aa.2003.105.2.333 }}</ref> In a later study, the same authors concluded that the effects Boas observed were likely the result of population-specific environmental effects such as changes in cultural practices for cradling infants, rather than the effects of a general "American environment" which caused populations in America to converge to a common cranial type, as Boas had suggested.<ref>{{cite journal | vauthors = Jantz RL, Logan MH | title = Why does head form change in children of immigrants? A reappraisal | journal = American Journal of Human Biology | volume = 22 | issue = 5 | pages = 702–707 | year = 2010 | pmid = 20737620 | doi = 10.1002/ajhb.21070 | s2cid = 12686512 }}</ref><ref>{{cite book | vauthors = Spradley MK, Weisensee K |chapter=Ancestry Estimation: The Importance, The History, and The Practice | veditors = Langley NR, Tersigni-Tarrant MT |title=Forensic Anthropology: A Comprehensive Introduction |edition=Second |year=2017 |pages=165–166 |publisher=CRC Press |isbn=978-1-4987-3612-1 }}</ref>

==Vertical cephalic index==
The vertical cephalic index, also known as the length-height index, was a less-commonly measured head ratio.<ref>{{Cite web |title= |url=https://www.merriam-webster.com/medical/length-height%20index}}</ref><ref>{{Cite journal |title= The Study of Vertical Cephalic Index (Length-Height Index) and Transverse Cephalic Index (Breadth-Height Index) of Andhra Region (India)|date=2013 |url=https://www.researchgate.net/publication/314386981 |doi=10.3126/ajms.v3i3.4650 |last1=Chandrashekhar |first1=Chikatapu |last2=Salve |first2=Vishal Manoharrao |journal=Asian Journal of Medical Sciences |volume=3 |issue=3 |pages=6–11 |doi-access=free }}</ref> In the vertical cephalic index model, humans beings were characterized by having either a chamaecranic (low-skulled), orthocranic (medium high-skulled), or hypsicranic (high-skulled) cephalic index or cranial index.

== Medicine ==
The cephalic index is also used in medicine, especially in the planning and effectiveness analysis of cranial deformity corrections.<ref>{{Cite journal |last1=Likus |first1=Wirginia |last2=Bajor |first2=Grzegorz |last3=Gruszczynska |first3=Katrzyna |last4=Baron |first4=Jan |last5=Markowski |first5=Jaroslaw |last6=Machnikowska-Sokolowska |first6=Magdalena |last7=Milka |first7=Daniela |last8=Lepich |first8=Tomasz |date=February 4, 2014 |title=Cephalic Index in the First Three Years of Life: Study of Children with Normal Brain Development Based on Computed Tomography |journal=TheScientificWorldJournal |volume=2014 |page=502836 |doi=10.1155/2014/502836 |pmid=24688395 |pmc=3933399 |doi-access=free }}</ref> The index is a useful tool in assessing the morphology of cranial deformities in clinical settings.<ref>{{Cite journal |last1=Nam |first1=Heesung |last2=Han |first2=Nami |last3=Eom |first3=Mi Ja |last4=Kook |first4=Minjung |last5=Kim |first5=Jeeyoung |date=2021-04-30 |title=Cephalic Index of Korean Children With Normal Brain Development During the First 7 Years of Life Based on Computed Tomography |url=http://www.e-arm.org/journal/view.php?number=4213 |journal=Annals of Rehabilitation Medicine |language=English |volume=45 |issue=2 |pages=141–149 |doi=10.5535/arm.20235 |pmid=33985316 |issn=2234-0645|pmc=8137378 }}</ref> The index is used while looking at the fetal head shape, and can change in certain situations (ex. breech presentation, [[Medicine:Rupture of membranes|ruptured membranes]], [[Biology:Twin|twin pregnancy]]).<ref>{{Cite web |last=Weerakkody |first=Yuranga |title=Cephalic index {{!}} Radiology Reference Article {{!}} Radiopaedia.org |url=https://radiopaedia.org/articles/cephalic-index?lang=us |access-date=2023-04-06 |website=Radiopaedia |language=en-US}}</ref>

== Modern use in animal breeding ==
The cephalic index is used in the categorisation of animals, especially breeds of dogs and cats. 

===Brachycephalic animals===
[[Image:Panting Frenchie.jpg|thumb|Brachycephalic French Bulldog, with visible indications of laboured breathing.]]
[[File:Brachycephalie.png|thumb|English Bulldog: Left: 1900–1920. Middle: Switzerland-Champion *1963 †1971. Right: Female *1985 †1993.]]
[[File:Boxer Dog Craniofacial Angle.jpg|thumb|Craniofacial angle of a Boxer]]

A brachycephalic skull is relatively broad and short (typically with the breadth at least 80% of the length). Dog breeds such as the pug are sometimes classified as "extreme brachycephalic".<ref>{{Cite web|url=https://www.thekennelclub.org.uk/health/for-owners/brachycephalic-health/|title=Brachycephalic Health|website=www.thekennelclub.org.uk|access-date=2020-02-17}}</ref> Because of the health issues brachycephaly is regarded as torture breeding<ref>FOUR PAWS International: ''[https://www.four-paws.org/campaigns-topics/topics/companion-animals/breeding-of-dogs-with-genetic-disorders/the-suffering-of-dogs-with-genetic-disorders The suffering of dogs with genetic disorders]''</ref><ref>Anne Fawcett, Vanessa Barrs, Magdoline Awad et al.: ''[https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6356869/ Consequences and Management of Canine Brachycephaly in Veterinary Practice: Perspectives from Australian Veterinarians and Veterinary Specialists]''</ref><ref>Border Wars: ''[http://www.border-wars.com/2011/07/torture-breeding.html Torture breeding]''</ref><ref>FECAVA: ''[https://www.fecava.org/policies-actions/healthy-breeding-3/ Brachycephalic issues: shared resources]''</ref> as it often leads to the brachycephalic airway obstructive syndrome. 

====List of brachycephalic dogs====
[[Image:Murlough Beach (05), February 2010.JPG|thumb|Breeds with less extreme brachycephalia, such as the Boxer, have less compromised thermoregulation and thus are more tolerant of vigorous exercise and heat.]]
<ref>{{Cite web |last=Lowrey |first=Sassafras |date=June 10, 2022 |title=Brachycephalic Dog Breeds: A Guide to Flat-Faced Dogs |url=https://www.akc.org/expert-advice/dog-breeds/brachycephalic-dog-breeds/ |access-date=2023-05-06 |website=American Kennel Club |language=en}}</ref>
{{div col|colwidth=20em}}
* Affenpinscher
* American Bulldog
* American Bully
* Boston Terrier
* Boxer
* Brussels Griffon
* Bulldog
* Bullmastiff
* Cane Corso
* Cavalier King Charles Spaniel
* Apple-headed Chihuahua
* Chow Chow
* Dogo Argentino
* Dogue de Bordeaux
* English Mastiff
* English Bulldog
* Fila Brasileiro
* French Bulldog
* Japanese Chin
* King Charles Spaniel
* Lhasa Apso
* Lowchen
* Neapolitan Mastiff
* Newfoundland
* Olde English Bulldogge
* Pekingese
* Perro de Presa Canario
* Pit bull
* Pug
* Pyrenean Mastiff
* Shar-Pei
* Shih Tzu
* Tibetan Spaniel
* Tosa
{{div col end}}

====List of brachycephalic cats====
[[File:Nipsu-Nappulan Non-Stop Exotic shorthair.JPG|thumb|An Exotic Shorthair]]
<ref>{{Cite web |title=Brachycephalic Breeds of Cats {{!}} ASPCA Pet Health Insurance |url=https://www.aspcapetinsurance.com/resources/brachycephalic-cats/ |access-date=2023-03-13 |website=www.aspcapetinsurance.com |language=en}}</ref><ref>{{Cite web |title=Breathing Problems in Flat-faced Cat Breeds {{!}} Purina |url=https://www.purina-arabia.com/articles/cats/health/symptoms/flat-faced-cats |access-date=2023-03-13 |website=www.purina-arabia.com |language=en-AE}}</ref>
{{div col|colwidth=20em}}
* British Shorthair
* Burmese cat
* Exotic Shorthair
* Himalayan cat
* Persian cat
* Scottish Fold
* [[Biology:White tiger#Defects|White tiger]]
{{div col end}}

==== List of brachycephalic pigs====
<ref name=":0">{{cite journal | vauthors = Geiger M, Schoenebeck JJ, Schneider RA, Schmidt MJ, Fischer MS, Sánchez-Villagra MR | title = Exceptional Changes in Skeletal Anatomy under Domestication: The Case of Brachycephaly | journal = Integrative Organismal Biology | volume = 3 | issue = 1 | pages = obab023 | date = 2021-08-14 | pmid = 34409262 | pmc = 8366567 | doi = 10.1093/iob/obab023 }}</ref>
* [[Biology:Middle White|Middle White]]
* Neijiang

==== List of brachycephalic rabbits ====
<ref name=":0" /><ref>{{Cite web |date=24 March 2017 |title=Brachy breeds – not just dogs! Rabbits too |url=https://rabbitwelfare.co.uk/brachy-breeds-not-just-dogs-rabbits-too/}}</ref>
* Lionhead rabbit
* Lop rabbit
* Netherland Dwarf rabbit
* Dwarf Papillon rabbit
* Dwarf Hotot rabbit
* Jersey Wooly rabbit
* American Fuzzylop rabbit

====Other====
* [[Biology:Giant panda|Giant panda]]
* Ross seal
* [[Biology:Spectacled bear|Spectacled bear]]
* [[Biology:Walrus|Walrus]]
* [[Biology:Wombat|Wombat]]

===Mesaticephalic animals===
[[Image:Labrador Retriever black portrait Ellis.jpg|thumb|Mesocephalic Labrador Retriever]]

A mesaticephalic skull is of intermediate length and width. Mesaticephalic skulls are not markedly brachycephalic or dolichocephalic. When dealing with animals, especially dogs, the more appropriate and commonly used term is not "mesocephalic", but rather "mesaticephalic", which is a ratio of head to nasal cavity.  The breeds below exemplify this category.<ref>{{Cite book | vauthors = Evans HE |year=1994 |title=Miller's Anatomy of the Dog |edition=3rd |location=Philadelphia |publisher=Saunders |isbn=9780721632001 |page=132 |oclc=827702042}}<!-- I've expanded the reference based on the available information; I hope the results are correct. Source for the additional details: https://www.goodreads.com/book/show/1203402.Miller_s_Anatomy_of_the_Dog . --></ref><ref>{{Cite encyclopedia |title=mesaticephalic |url=http://medical-dictionary.thefreedictionary.com/mesaticephalic |work=Farlex Partner Medical Dictionary |year=2012 |via=[[The Free Dictionary]] |access-date=2 January 2019}}</ref>

====List of mesaticephalic canines====
{{unsourced section|date=December 2021}}
{{div col|colwidth=20em}}
* African Wild Dog
* Alaskan Malamute
* almost all spaniels
* almost all spitz, except for the Chow Chow
* American Eskimo Dog
* American Foxhound
* Appenzeller Sennenhund
* Australian Cattle Dog
* Australian Shepherd
* Basenji
* Beagle
* Bearded Collie
* Beauceron
* Belgian Malinois
* Belgian Sheepdog
* Bernese Mountain Dog
* Bichon Frisé
* Black and Tan Coonhound
* Border Collie
* Cardigan Welsh Corgi
* Chesapeake Bay Retriever
* pear- and deer-headed Chihuahuas
* Chinese Crested
* Chinook
* Curly-Coated Retriever
* Dalmatian
* [[Biology:Dhole|Dhole]]
* English Foxhound
* Field Spaniel
* Finnish Lapphund
* Finnish Spitz
* Flat-Coated Retriever
* German Shorthaired Pointer
* German Wirehaired Pointer 
* [[Biology:German Spitz|German Spitz]]
* Golden Retriever
* Irish Setter
* Komondor
* Labrador Retriever
* Miniature Pinscher
* Pomeranian
* Poodle (Miniature and Toy)
* most terriers
* Mudi
* Pembroke Welsh Corgi
* Puli
* Rottweiler
* Samoyed
* Siberian Husky
* St. Bernard
* Vizsla
* Weimaraner
* Wirehaired Vizsla
* Xoloitzcuintle
{{div col end}}

====List of mesaticephalic cats====
{{unsourced section|date=December 2021}}
Note: Almost all domestic felines are mesaticephalic
{{div col|colwidth=20em}}
* Abyssinian
* American Shorthair
* American Bobtail
* [[Biology:Bengal cat|Bengal cat]]
* Birman
* Bombay cat
* Burmese cat
* Chartreux
* Chausie
* Colorpoint Shorthair
* Cymric cat
* Egyptian Mau
* [[Biology:Felid hybrid|Felid hybrid]]s
* ''[[Biology:Felis|Felis]]'', or small cats
* Maine Coon
* Manx
* Munchkin cat
* Norwegian forest cat 
* Ocicat
* [[Biology:Pallas's cat|Pallas's cat]]
* Ragdoll
* Russian Blue
* Russian White, Black and Tabby
* Selkirk Rex
* Siberian cat
* Somali
* Toyger
* Turkish Angora
* Turkish Van

{{div col end}}

====List of mesaticephalic rabbits====
* Dutch rabbit
* Mini Rex
* Polish rabbit
* New Zealand rabbit
* American Sable

====Other====
* [[Biology:Aardwolf|Aardwolf]]
* [[Biology:Alligator|Alligator]]
* [[Biology:American black bear|American black bear]]
* [[Biology:Brown bear|Brown bear]]
* [[Biology:Brown hyena|Brown hyena]]
* [[Biology:Fur seal|Fur seal]]
* [[Biology:Guinea pig|Guinea pig]]
* [[Biology:Leopard seal|Leopard seal]]
* [[Biology:Raccoon|Raccoon]]
* [[Biology:Sea lion|Sea lion]]
* Sloth bear
* [[Biology:Spotted hyena|Spotted hyena]]
* [[Biology:Striped hyena|Striped hyena]]
* Sun bear
* Tasmanian devil

===Dolichocephalic animals===
[[Image:Kufa charta - borzoja.jpg|thumb|Dolichocephalic Borzoi]]
A dolichocephalic skull is relatively long-headed (typically with the breadth less than 80% or 75% of the length).

Note: Almost all representatives of the infraphylum [[Biology:Gnathostomata|Gnathostomata]] (with rare exceptions) are dolichocephalic.

====List of dolichocephalic canids====
{{unsourced section|date=December 2021}}
{{div col|colwidth=20em}}
Note: Almost all canidae are dolichocephalic
* Afghan Hound
* Airedale Terrier
* Azawakh
* Basset Hound
* Bedlington Terrier
* Bloodhound
* Borzoi
* Bull terrier
* Cesky Terrier
* [[Biology:Coyote|Coyote]]
* Dachshund
* Doberman Pinscher
* [[Biology:Dingo|Dingo]]
* Fox Terrier
* Galgo Español
* German Shepherd Dog
* Great Dane
* Greyhound
* Irish Terrier
* Irish Wolfhound
* Italian Greyhound
* Kangaroo hound
* Kanni
* Kerry Blue Terrier
* Khalag Tazi
* Long dog
* Lurcher
* Manchester Terrier
* Miniature Bull Terrier
* Peruvian Inca Orchid
* Pharaoh Hound
* Poodle (Standard)
* Rampur Greyhound
* [[Biology:Red fox|Red fox]]
* Rough Collie
* Russian Black Terrier
* Saluki
* Schnauzer
* Scottish Deerhound
* Scottish Terrier
* Sealyham Terrier
* Serbian Hound
* Shetland Sheepdog
* Silken Windhound
* Sloughi
* Smooth Collie
* Taigan
* Welsh Terrier
* Whippet
* [[Biology:Wolf|Wolf]]
{{div col end}}

{{Anchor|List of dolicocephalic felines|reason=This is the old section name. Spelling of "dolichocephalic" was corrected on 21 February 2018.}}

====List of dolichocephalic felines====
{{unsourced section|date=December 2021}}
{{div col|colwidth=12em}}
* Balinese
* Devon Rex
* Donskoy
* [[Biology:Jaguar|Jaguar]]
* Javanese
* [[Biology:Leopard|Leopard]]
* [[Biology:Lion|Lion]]
* [[Biology:Ocelot|Ocelot]]
* Oriental Bicolor and Tricolor
* Oriental Longhair
* Oriental Shorthair
* [[Biology:Panthera hybrid|''Panthera'' hybrid]]
* Peterbald
* [[Biology:Machairodontinae|Sabertooth cats]]
* Savannah
* Siamese
* [[Biology:Snow leopard|Snow leopard]]
* Sphynx
* [[Biology:Tiger|Tiger]]
{{div col end}}

{{Anchor|List of dolicocephalic leporids|reason=This is the old section name. Spelling of "dolichocephalic" was corrected on 21 February 2018.}}

====List of dolichocephalic leporids====
*English Spot
*[[Biology:English Lop|English Lop]]
*Belgian Hare
*All true [[Biology:Hare|hare]]s

====Other====
{{div col|colwidth=12em}}
* [[Biology:Bontebok|Bontebok]]
* [[Biology:Crocodile|Crocodile]]
* Cow
* Domestic horse
* [[Biology:Donkey|Donkey]]
* [[Biology:Gharial|Gharial]]
* Grevy's zebra
* [[Biology:Hartebeest|Hartebeest]]
* [[Biology:Hyrax|Hyrax]]
* [[Biology:Kangaroo|Kangaroo]]
* Mule
* [[Biology:Onager|Onager]]
* Plains zebra
* [[Biology:Polar bear|Polar bear]]
* [[Biology:Thylacine|Thylacine]]
* [[Biology:Warthog|Warthog]]
* [[Biology:Whale|Whale]]
* Wild boar
* [[Biology:Wildebeest|Wildebeest]]
{{div col end}}

== See also ==
* [[Biology:Cephalic index in cats and dogs|Cephalic index in cats and dogs]]
* [[Medicine:Craniometry|Craniometry]]
* [[Philosophy:Phrenology|Phrenology]]
* Human skull

== References ==
{{reflist}}

== External links ==
{{EB1911 poster|Cephalic Index}}
* [https://web.archive.org/web/20120218134744/http://www.medfriendly.com/cephalicindex.php5 Cephalic index]
* [http://frenchievets.ning.com/ Brachycephalic Experienced Veterinarians Database] {{Webarchive|url=https://web.archive.org/web/20070830141352/http://frenchievets.ning.com/ |date=30 August 2007 }}

{{DEFAULTSORT:Cephalic Index}}
[[Category:Biological anthropology]]

{{Sourceattribution|Cephalic index}}