Brown-throated Sloth, skull from lateral
Unknown author<span style="display: none;">Unknown author</span>
1871
<i>Proceedings of the Zoological Society of London</i> (<a rel="nofollow" class="external text" href="https://archive.org/details/proceedingsofgen71zool">vol. 1871</a>, <a rel="nofollow" class="external text" href="https://archive.org/stream/proceedingsofgen71zool#page/445/mode/1up">page 445</a>)