Dewaele Leonard, Lambert Olivier, Louwye Stephen
Department of Geology, Ghent University, Ghent, Belgium.
'Earth and History of Life', Royal Belgian Institute of Natural Sciences, Brussels, Belgium.
R Soc Open Sci. 2018 May 9;5(5):171669. doi: 10.1098/rsos.171669. eCollection 2018 May.
Historically, had been one of the few genera of extinct Phocidae (true seals) that served as a wastebin taxon. Consequently, it did neither aid in understanding phylogenetic relationships of extinct Phocidae, nor in understanding seal diversity in deep time. This urged the reassessment of the genus. Before our review, included five different species: , , and from Belgium; from Italy; and ? from the east coast USA. In this work we redescribe the fossil record of the genus, retaining the type species . and are reassigned to the new phocine genus . is renamed and considered a stem-monachine (). The holotype of the monachine ? requires further study pending the discovery of new fossil material that could be attributed to the same taxon. Reinvestigating the stratigraphic context reveals that most likely represents one of the two oldest named phocid seals, or even the oldest, dated to the late Oligocene-earliest Miocene. Our results allow questioning the widespread idea that Phocidae originated in the western Atlantic and better appreciate their palaeobiogeography during the late Oligocene-Miocene interval in the North Atlantic realm.
从历史上看， 一直是已灭绝的海豹科（真海豹）中少数几个充当“垃圾桶分类单元”的属之一。因此，它既无助于理解已灭绝海豹科的系统发育关系，也无助于理解远古时期海豹的多样性。这促使对该属进行重新评估。在我们进行综述之前， 包含五个不同的物种：来自比利时的 、 和 ；来自意大利的 ；以及来自美国东海岸的 ？在这项工作中，我们重新描述了该属的化石记录，保留了模式种 。 和 被重新归入新的海豹属 。 被重新命名并被认为是一种干群海豹（ ）。海豹属 的正模标本需要进一步研究，以待发现可归属于同一分类单元的新化石材料。重新研究地层背景表明， 很可能代表了最早命名的两种海豹科动物之一，甚至是最古老的，可追溯到晚渐新世 - 早中新世。我们的研究结果对海豹科起源于西大西洋这一普遍观点提出了质疑，并能更好地认识它们在北大西洋地区晚渐新世 - 中新世期间的古生物地理学。
