Work Description

Date: 22 February, 2024

Dataset Title: Cichlinae Pharyngeal Jaw Landmark data

Dataset Contact: Benjamin Nicholas [email protected]

Dataset Creators:
Name:Benjamin P. Nicholas
Email: [email protected]
Institution: University of Michigan
ORCID:0009-0007-6190-4571

Name:Hernán López-Fernández
Email: [email protected]
Institution: University of Michigan
ORCID:0000-0003-0270-1671

Funding: University of Michigan

Key Points
- We perform the first comparative analyses of the whole pharyngeal jaw in Neotropical Cichlids
- Both Upper and Lower Pharyngeal jaws showed evidence of recent accumulations of disparity
- This is contrary to previous studies of other trait dimensions in Neotropical Cichlids which found evidence of early bursts, a signature of adaptive radiations.

Research Overview:
Understanding how continental assemblages have diversified can be difficult as they are products of extinction, biogeographic rearrangements, and changing environments over millions of years. Much of our knowledge of adaptive radiations stems from relatively recent, insular-like systems. However, increasing evidence supports the idea that adaptive radiations have a major role in hyper diverse continental radiations like Neotropical cichlids. This primarily riverine group has undergone adaptive diversification in many into ecologically, morphologically, and behaviorally complex lineages. Surprisingly, the macroevolutionary patterns of the entire pharyngeal jaw is relatively understudied in Neotropical cichlids. In this study we use µCT scans to characterize the entire pharyngeal system across
Neotropical cichlids to test for signatures of adaptive radiation. We describe the morphological diversity of the upper and lower pharyngeal jaw, fit models of evolutionary divergence, and measure morphological disparity through time and among clades. Until now, studies of various axes of diversification in Cichlinae found a congruent signals an early bursts of divergence in multiple trait dimensions, however we find no evidence of an early burst in the pharyngeal jaws. We find evidence of
highly specialized pharyngeal jaws establishing early in the continental radiation and also evidence of recent morphological divergence in the three major tribes of Cichlinae. Our results further highlight the
necessity to study adaptively radiating lineages in multiple trait dimensions as some axes of diversification may be overlooked.

Methodology:
Museum specimens of Neotropical Cichlids from the UMMZ, AMNH, and ROM were CT scanned at the RMC at University of Michigan. Relevant morphology (Pharyngeal jaw, neurocranium, and urohyal) was segmented out in Dragonfly ORS and converted into 3d meshes. In the Program 3D slicer, landmarks were placed on the left side of specimens according to the landmarking scheme in Nicholas and López-Fernández 2024. Landmarks were placed as either homologous points, or as curves using semi-sliding landmarks. The landmark files contain 204 landmarks, however only landmarks 31:50, 60:123, 137:169, 180 and 204 were used in our study.

Files contained here:
There are 95 .json files containing 204 landmarks from Neotropical Cichlids (subfamily
Cichlinae). A list of the landmarks and their descriptions cans be found in the supplemental
materials of the related publication along with the R scripts to analyze the landmarks.

The files are named as such
-Genus_species.mrk.json

Key to important labels in .json file
id = Landmark number
description = fixed or semi
position = landmark coordinates (X, Y, Z)

Related Publication:
Nicholas, B., & López-Fernández, H. (2024). Analysis of the whole pharyngeal jaw adds nuance to the continental radiation of Neotropical cichlids. Evolutionary Journal of the Linnean Society, 3(1), kzae038.

Use and Access
This data is made available under Attribution-NonCommerical 4.0 International license CC BY-NC 4.0.

To Cite Data:
Nicholas, B., López-Fernández, H. Cichlinae Pharyngeal Jaw Landmark data [Data set], University of Michigan - Deep Blue Data. https://doi.org/10.7302/ay7y-4s12