DOI: 10.5061/dryad.wstqjq2vz
title: Data from: Heritability in the Rhesus macaque (Macaca mulatta) vertebral column

description: The vertebral column plays a central role in primate locomotion and
 positional behavior. Understanding its evolution therefore has the
 potential to clarify evolutionary processes that have occurred in the
 primate lineage as well as the specific behaviors of extinct primates.
 However, in order to understand primate vertebral anatomy, it is important
 to determine how much of this anatomy is heritable and how much develops
 as a response to environmental factors during life. We estimated
 heritability for vertebral counts as well as typical cervical, thoracic,
 and lumbar elements from 210 individuals from the pedigreed Cayo Santiago
 Macaca mulatta skeletal collection. We found moderate heritability of
 vertebral counts (h2 =0.216–0.326), but with strong heritability of the
 type of variation (e.g., a tendency to meristic or homeotic change) in the
 vertebral count (h2 =0.599), suggesting a possible explanation for high
 variability in vertebral numbers among the hominoids in particular. The
 moderate heritability of vertebral count also suggests that vertebral
 count is an unsuitable metric for estimating the ancestral state for some
 taxa. We found strong heritability in the morphology of cervical and upper
 lumbar zygapophyseal facets (h2 =0.548–0.550) and the thoracic spinous
 processes (h2 =0.609–0.761), including high heritability of the spinous
 process angle in the upper thoracic and upper lumbar elements (h2
 =0.649–0.752). We suggest these are related to maintaining stability in
 the cervical and lumbar regions, and reducing motion in the thoracic
 region, respectively. We propose that spinous processes may contain
 greater phylogenetic information, whereas transverse processes may contain
 greater information of function ‘in life’. We also found important size
 effects, suggesting that size is the most heritable component of overall
 form and largely responsible for intertrait differences. This suggests
 that it is inappropriate to indiscriminately remove size effects from
 morphological comparisons.
description: This dataset includes 3D coordinate data from cervical vertebrae
 3 and 5 (C3, C5), thoracic vertebrae 3 and 9 (T3, T9), and lumbar
 vertebrae 2 and 5 (L2, L5) from a sample of 132 female and 78 male Rhesus
 macaques (<em>Macaca mulatta</em>) from the free-ranging
 colony on Cayo Santiago, Puerto Rico. All individuals
 were adult as assessed from absolute age, fusion of the sphenooccipital
 synchondrosis, eruption of the last molar, and fusion of long bone
 epiphyses. 3D surface scans were collected
 using an Artec 3D Space Spider accurate up to 0.05 mm and with resolution
 of up to 0.1 mm. 3D coordinates were then collected using Checkpoint
 software (Stratovan Corporation, 2023). Coordinate data is presented in
 millimeters (mm). A limited set of linear measurements extracted from the
 data present average intraobserver errors between 1.55% and
 3.33%. Specific coordinates are described in the Readme
 file.
description: # Heritability in the Rhesus macaque (Macaca mulatta) vertebral column
 [https://doi.org/10.5061/dryad.wstqjq2vz](https://doi.org/10.5061/dryad.wstqjq2vz) We present 3D coordinate data from cervical vertebrae 3 and 5 (C3, C5), thoracic vertebrae 3 and 9 (T3, T9), and lumbar vertebrae 2 and 5 (L2, L5) from a sample of 132 female and 78 male Rhesus macaques (*Macaca mulatta*) from the free-ranging colony on Cayo Santiago, Puerto Rico. All individuals were adult as assessed from absolute age, fusion of the sphenooccipital synchondrosis, eruption of the last molar, and fusion of long bone epiphyses. ## Description of the data and file structure We include six separate files, one for each vertebral element: c3.csv, c5.csv, t3.csv, t9.csv, l2.csv, l5.csv Data are provided in CSV files with each row representing one individual. Data are 3D coordinate data for 47 individual landmarks, which have been screened for coordinate inversions (e.g. right and left landmarks flipped) and similar errors but have not been otherwise modified. Data are presented in millimeters (mm). Missing data are marked by NA. Macaques have 7 cervical, 12 thoracic, and 7 lumbar elements modally. Individuals with nonmodal formulae have been treated as follows: * We used C4 instead of C5 for individuals with 6 cervical elements to maintain the profile of the typical vertebral column. This included a total of 2 individuals. The ultimate and penultimate cervical elements both show distinct morphological features that differentiate them from typical elements, regardless of total number. * No adjustments were made for variation in thoracic element number. However, macaques also vary in the position of the transitional vertebra, which marks the transition from thoracic-like to lumbar-like zygapophyseal facets, independently of the total number of thoracic elements. In the majority of individuals, the transitional vertebra occurs at T10, so that T9 is the pre-transitional vertebra. We prioritized maintaining the profile of the typical vertebral column by always collecting the pre-transitional vertebra. In our sample, a total of 8 individuals had a non-modal transitional position, including T8 or T10. There were no significant differences between datasets when these individuals were included or excluded (Levene's Test F=0.00-3.39, P =0.067-0.991, Kruskal-Wallis Chi-squared =0.00-4.53, P =0.104-1.00) as reported in the accompanying manuscript. * No adjustments were made for variation in lumbar element number. Abbreviations: * "cprc_cat" is the Caribbean Primate Research Center catalogue number for that specimen. * In the 'sex' column, "M" and "F" stand for "Male" and "Female" respectively. * "RC" stands for "raw coordinate", a total of 141 coordinates are present (3 coordinates per landmark, 47 landmarks) * "NA" indicates missing data We include a full landmark set, however not all landmarks were analyzed for error directly or used for publication. Landmarks 5, 7, and 8 and their left-side equivalents were found to be non-repeatable across observers. Landmarks 32 and 33 were also found to be non-repeatable across observers. Landmarks collected are as follows: | **Number** | **Landmark Name** | **Landmark Description** | **Raw Coordinates (“RC”) corresponding to this landmark in data files** | | :--------- | :-------------------------------------- | :----------------------------------------------------------------------------------------------------------------------------------- | :---------------------------------------------------------------------- | | 1 | Cranial-ventral body | Midline point on ventral edge of the vertebral body, measured on cranial surface | RC1, RC2, RC3 | | 2 | Cranial-transverse body (R) | Most lateral point on the right of the vertebral body, measured on cranial surface | RC4, RC5, RC6 | | 3 | As 2, on left side | | RC7, RC8, RC9 | | 4 | Cranial-dorsal body | Midline point on dorsal edge of the vertebral body, measured on cranial surface |   RC10, RC11, RC12 | | 5 | Cranial-medial pedicle (R) | Point on the medial cranial margin of the pedicle, measured along the transverse midlines | RC13, RC14, RC15 | | 6 | Cranial maximum pedicle (R) | Most cranial point on the cranial margin of the right pedicle, measured along the transverse midline | RC16, RC17, RC18 | | 7 | Cranial-lateral pedicle (R) | Point on the lateral cranial margin of the right pedicle, measured along the transverse midline | RC19, RC20, RC21 | | 8 | Midline breadth pedicle (R) | Point on lateral side of the right pedicle, measured at the craniocaudal and transverse midline | RC22, RC23, RC24 | | 9 | Caudal-lateral pedicle (R) | Most caudal point on the caudal margin of the right pedicle, measured along the transverse midline | RC25, RC26, RC27 | | 10-14 | As 5-9, on left side | | RC28, RC29, RC30 | | 15 | Cranial maximum transverse process (R) | Most cranial point on lateral margin of right transverse process | RC43, RC44, RC45 | | 16 | Lateral midpoint transverse process (R) | Most lateral point on lateral margin of right transverse process or, if no projecting lateral point, midline point on lateral margin | RC46, RC47, RC48 | | 17 | Caudal maximum transverse process (R) | Most caudal point on lateral margin of right transverse process | RC49, RC50, RC51 | | 18-20 | As 15-17, on left side | | RC52, RC53, RC54 | | 21 | Cranial pre-zygapophysis (R) | Most cranial point on the margin of the right pre-zygapophysis | RC61, RC62, RC63 | | 22 | Lateral pre-zygapophysis (R) | Most lateral point on the margin of the right pre-zygapophysis | RC64, RC65, RC66 | | 23 | Caudal pre-zygapophysis (R) | Most caudal point on the margin of the right pre-zygapophysis | RC67, RC68, RC69 | | 24 | Medial pre-zygapophysis (R) | Most medial point on the margin of the right pre-zygapophysis | RC70, RC71, RC72 | | 25-28 | As 21-24, on left side | | RC73, RC74, RC75 | | 29 | Midline canal | Midline point on the cranial, dorsal margin of the neural arch, ventral to the formation of the neural arch | RC85, RC86, RC87 | | 30 | Ventral-cranial spine | Midline point on cranial, ventral margin of vertebral spine, where spine separates from laminae | RC88, RC89, RC90 | | 31 | Dorsal-cranial spine | Most cranial point on dorsal margin of vertebral spine | RC91, RC92, RC93 | | 32 | Lateral spine (R) | Most lateral point on right dorsal margin of vertebral spine | RC94, RC95, RC96 | | 33 | As 32, on left side | | RC97, RC98, RC99 | | 34 | Dorsal-caudal spine | Most caudal point on dorsal margin of vertebral spine | RC100, RC101, RC102 | | 35 | Ventral-caudal spine | Midline point on caudal, ventral margin of vertebral spine, where spine meets vertebral canal | RC103, RC104, RC105 | | 36 | Cranial post-zygapophysis (R) | Most cranial point on the margin of the right post-zygapophysis | RC106, RC107, RC108 | | 37 | Lateral post-zygapophysis (R) | Most lateral point on the margin of the right post-zygapophysis | RC109, RC110, RC111 | | 38 | Caudal post-zygapophysis (R) | Most caudal point on the margin of the right post-zygapophysis | RC112, RC113, RC114 | | 39 | Medial post-zygapophysis (R) | Most medial point on the margin of the right post-zygapophysis | RC115, RC116, RC117 | | 40-43 | As 36-39, on left side | | RC118, RC119, RC120 | | 44 | Caudal-ventral body | Midline point on ventral edge of the vertebral body, measured on caudal surface | RC130, RC131, RC132 | | 45 | Caudal-transverse body (R) | Most lateral point on the right of the vertebral body, measured on caudal surface | RC133, RC134, RC135 | | 46 | Caudal-transverse body (L) | Most lateral point on the left of the vertebral body, measured on caudal surface | RC136, RC137, RC138 | | 47 | Caudal-dorsal body | Midline point on dorsal edge of the vertebral body, measured on caudal surface | RC139, RC140, RC141 |