Tactile bill-tip organs in seabirds suggests conservation of a deep avian symplesiomorphy

Birds’ bills are their main tactile interface with the outside world. Tactile bill-tip organs associated with specialised foraging techniques are present in several bird groups, yet remain understudied in most clades. One example is Austrodyptornithes, the major seabird clade uniting Procellariiformes (albatrosses and petrels) and Sphenisciformes (penguins). Here, we describe the mechanoreceptor arrangement and neurovascular anatomy in the premaxillae of Austrodyptornithes. Using a wide phylogenetic sample of extant birds (361 species), we show that albatrosses and penguins exhibit complex tactile bill-tip anatomies, comparable to birds with known bill-tip organs, despite not being known to use tactile foraging. Petrels (Procellariidae, Hydrobatidae and Oceanitidae) lack these morphologies, indicating an evolutionary transition in bill-tip mechanosensitivity within Procellariiformes. The bill-tip organ in Austrodyptornithes may be functionally related to nocturnal foraging and prey dete..., , , # Data from: Tactile bill-tip organs in seabirds suggests conservation of a deep avian symplesiomorphy

[https://doi.org/10.5061/dryad.9w0vt4bq2](https://doi.org/10.5061/dryad.9w0vt4bq2)

This is the data and R code supporting our publication. Data were collected from museum specimens of bird skulls from photographs, in order to assess the presence of tactile neurovascular structures in the beaks of Austrodyptornithine seabirds in relation to all extant birds. 

## Description of the data and file structure

The R script requires the latest version of RStudio to run, all packages required are listed in the script at the start. All datasets (as .csv files) are utilized by the R script \"seabird beaks code.R\". The script will import the necessary data, so long as the files are all saved in the same directory. 

The species_tree.tre file is the time-scaled phylogeny used, based on two previously published trees (see methods section of paper for details): 

1. Cooney CR, Bright JA, Capp EJR,...

鸟类的喙是其与外界进行触觉交互的核心界面。与特化觅食策略相关的触觉喙端器官广泛存在于多个鸟类类群中，但绝大多数演化支对此类结构的研究仍有待深入。其中一类典型代表为南鳍鸟类（Austrodyptornithes），这一主要海鸟演化支涵盖了鹱形目（Procellariiformes，包括信天翁与海燕）以及企鹅目（Sphenisciformes，即企鹅）。

本研究对南鳍鸟类前颌骨中的机械感受器排布与神经血管解剖特征进行了系统描述。我们通过涵盖361个现存鸟类物种的广泛系统发育采样样本开展分析，结果显示：尽管信天翁与企鹅尚未被观测到利用触觉进行觅食，但二者均具备复杂的触觉喙端解剖结构，其复杂程度与已知拥有喙端器官的鸟类相当。海燕类群（包括鹱科、海燕科与远洋海燕科）则缺乏此类形态结构，这表明鹱形目内部的喙端机械敏感性存在演化转变。

南鳍鸟类的喙端器官可能与夜行觅食及猎物探测功能相关……

# 数据来源：《海鸟的触觉喙端器官揭示鸟类深层共祖特征的保守性》（Tactile bill-tip organs in seabirds suggests conservation of a deep avian symplesiomorphy）
https://doi.org/10.5061/dryad.9w0vt4bq2

本数据集与配套R代码用于支撑本研究成果发表。研究数据通过拍摄博物馆馆藏鸟类头骨标本的照片采集所得，旨在评估南鳍海鸟喙部是否存在触觉神经血管结构，并与所有现存鸟类开展对比分析。

## 数据与文件结构说明
本R脚本需使用最新版本的RStudio运行，所需全部依赖包已在脚本开头列明。所有数据集均以.csv格式存储，将由R脚本"seabird beaks code.R"调用。只需将所有文件保存至同一目录下，脚本即可自动导入所需数据。

物种树文件species_tree.tre为本次研究所使用的时间校准系统发育树，其构建基于两篇已发表的系统发育树（详见论文方法部分）：
1. Cooney CR, Bright JA, Capp EJR,...