新南威尔士大学研究人员在澳大利亚昆士兰州西北部的Riversleigh世界遗产地发现了三个新的已灭绝袋鼠类物种[1]。这一发现重新定义了对澳大利亚有袋动物演化史的认识，研究团队确认这些物种属于一个此前未知的古老袋鼠目——Keeunamorphia目[1]。
Keeunamorphia目在约1800万年前存活于澳大利亚，该物种群体的存活时间跨越约3500万年，最终在约1500万年前灭绝[1]。这些新发现的物种均为体重在25至200克之间的小型昆虫食性动物[1]。由新南威尔士大学古生物学家Tim Churchill博士主导的研究指出，Keeunamorphia目"不仅是一个新的目级分类，而且可能是所有澳大利亚有袋动物中最古老的谱系"[1]。
这项发现颠覆了长期以来关于澳大利亚有袋动物起源的传统认识。Churchill博士指出，"进化历史远比想象中复杂得多，并非只是一个群体在大陆与南极洲分离后演化成澳大利亚所有有袋动物"[1]。研究表明，有袋动物抵达澳大利亚的时间超过5500万年前[1]，该研究已于2026年发表在《古生物学杂志》上[1]。
Researchers at the University of New South Wales have identified three new extinct marsupial species belonging to a previously unknown ancient order called Keeunamorphia, fundamentally reshaping our understanding of marsupial evolution in Australia [1]. The discovery, announced on July 19, 2026, was made at the Riversleigh World Heritage site in northwestern Queensland and challenges the long-held scientific consensus that all Australian marsupials descended from a single ancestral lineage [1].
The newly identified species, which lived approximately 18 million years ago, were small insectivorous animals weighing between 25 and 200 grams [1]. The Keeunamorphia order itself persisted for roughly 35 million years before going extinct about 15 million years ago [1]. According to paleontologist Tim Churchill of the University of New South Wales, who led the research, "Not only is it a new order, it could also be the most ancient lineage of all Australian marsupials" [1]. The findings, published in the Journal of Paleontology in 2026, indicate that marsupials first arrived in Australia more than 55 million years ago and reveal an evolutionary history considerably more complex than previously understood [1]. As Churchill explained, "Evolutionary history is a lot more complex than just one group leading to all of Australia's marsupials after being left behind when the continent broke off from Antarctica" [1].