TABLE 1. Species level data composition. Species abundances of select phylogenetic classes, total species, and the number of habitat types within each sub-epoch are listed. Epoch and sub-epoch ages correspond to the ages of their base.1 Species level data composition. Species abundances of select phylogenetic classes, total species, and the number of habitat types within each sub-epoch are listed. Epoch and sub-epoch ages correspond to the ages of their base.

	Interval	Time (Ma)	Duration (m.y.)	Bivalve Species	Gastropod Species	Total Species	Habitat Types
	Holocene	0.00	0.00	241	279	651	15
	Pleistocene	2.6	2.59	1188	1835	4017	29
	Pliocene	5.3	2.7	1324	1891	4644	28
	late Miocene	11.6	6.3	1258	1422	3568	33
	middle Miocene	16.0	4.4	1374	1286	4081	33
	early Miocene	23.0	7.0	1439	1813	4441	32
	late Oligocene	28.4	5.4	597	412	1518	30
	early Oligocene	33.9	5.5	721	699	1792	25
	late Eocene	40.4	6.5	926	1287	3419	34
	middle Eocene	48.6	8.2	954	1020	3002	32
	early Eocene	55.8	7.2	329	475	1377	19