Supplementary_materials_S2

Complete R code for all analyses and figures used in the paper

Supplementary_materials_S3

RData file containing polygon data for all land regions through the Mesozoic. Use in conjunction with R code contained in Supplementary_materials_S2.R in this same repository

Supplementary Methods from The fragmentation of Pangaea and Mesozoic terrestrial vertebrate biodiversity

During the Mesozoic (245–66 million years ago), terrestrial regions underwent a massive shift in their size, position and connectivity. At the beginning of the era, the land masses were joined into a single supercontinent called Pangaea. However, by the end of the Mesozoic, terrestrial regions had become highly fragmented, both due to the drifting apart of the continental plates and the extremely high sea levels that flooded and divided many regions. How terrestrial biodiversity was affected by this fragmentation and large-scale flooding of the Earth's landmasses is uncertain. Based on a model using the species–area relationship (SAR), terrestrial vertebrate biodiversity would be expected to nearly double through the Mesozoic due to continental fragmentation, despite a decrease of 24% in total terrestrial area. Previous studies of Mesozoic vertebrates have generally found increases in terrestrial diversity towards the end of the era, though these increases are often attributed to intrinsic or climatic factors. Instead, continental fragmentation over this time may largely explain any observed increase in terrestrial biodiversity. This study demonstrates the importance that non-intrinsic effects can have on the taxonomic success of a group, and the importance of geography to understanding past biodiversity

Dunvegan ossicle histology.

<p>Composite mosaic image of thin section through ossicle of TMP 2012.054.0002 in cross-polarized light. Orientation uncertain. Scale bar equals 1.0 mm.</p

Ossicle osteocyte lacunae.

<p>Comparison of osteocyte lacuna morphology in primary (A) and secondary tissue (B) in an ossicle of TMP 2012.054.0002. Orientation uncertain. Scale bar equals 0.10 mm.</p

Locality map.

<p>A) Overview map showing location of inset map (B). B) Map of the Peace Country with major rivers and towns indicated. The fossil locality is denoted by a black star.</p

Dunvegan ossicle morphology.

<p>Ankylosaur ossicles (TMP.2012.054.0002) from the Cenomanian Dunvegan Formation, near the Peace River, British Columbia, Canada, in external and basal views. Scale bar equals 1.0 mm.</p

Primary ossicle tissues.

<p>Details of primary tissue in ossicle of TMP 2012.054.0002. A) Plane-polarized light showing zonation (growth marks indicated by arrowheads). B) Cross-polarized light showing ISFB.</p