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Edmond
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火山岩發現脊椎動物化石

大家沒有看錯, 最近科學家在土耳其的火山岩中，發現了距今已超過九百萬年歷史的犀牛頭骨化石，並且證明犀牛生前是被高溫瞬間煮熟致死。

中文報導如下:

科學家指出，全球不到2％的化石可以被完整地保存在火山岩裡。法國一所大學科學家最近從土耳其的火山岩中，發現了距今已超過九百萬年歷史的犀牛頭骨化石，並且證明犀牛生前是被高溫瞬間煮熟致死。科學家指出，有機物質經常被火山噴發後摧毀殆盡，因此這種化石相當罕見。
法國蒙彼利埃大學從土耳其的火山岩發現，一場距今約920萬年前火山噴發後，一頭犀牛瞬間被高溫燒死，之後被完整地保存在火山岩裡，當時這種犀牛在地中海地區東部一帶相當常見，科學家從不尋常的特徵觀察後得知，當時這隻犀牛應該是被攝氏500度以上的高溫煮熟致死，與西元79年義大利的維蘇威火山大爆發類似。
科學家安東尼指出，當時犀牛遇到熔漿時瞬間立即死亡，再加上高溫導致急速脫水，在岩漿流動過程中造成頭部與身體分離，最後犀牛頭顱則被帶到距離當初火山噴發地點北方30公里外。
安東尼說，過去從火山灰中經常可以發現軟體動物的化石，但是有機物質因為會被火山噴發後造成的高溫摧毀殆盡，因此犀牛頭骨化石能夠保留下來實屬難得。
今年初，日本福井縣恐龍博物館也展示了日本地區最古老的犀牛化石，距今已經超過1800萬年。博物館表示，犀牛化石在2009年十一月後陸續發現後，數量多達一百件，估計這隻犀牛身長約2.4公尺，死亡前應該棲息在沼澤或河邊地帶，因此也證明了當時的日本群島，的確曾與亞洲大陸相連。

本次研究結果刊登在《PLOS ONE》期刊。

英文原文
A Rhinocerotid Skull Cooked-to-Death in a 9.2 Ma-Old Ignimbrite Flow of Turkey

References
Pierre-Olivier Antoine1*, Maeva J. Orliac1,2, Gokhan Atici3, Inan Ulusoy4, Erdal Sen4, H. Evren Çubukçu4, Ebru Albayrak5, Neşe Oyal5, Erkan Aydar4, Sevket Sen6
1 Institut des Sciences de l’Évolution, UMR-CNRS 5554, CC064, Université Montpellier 2, Montpellier, France, 2 Department of African Zoology, Royal Museum for Central Africa, Tervuren, Belgium, 3 Department of Geology, General Directorate of MTA, Ankara, Turkey, 4 Hacettepe University Department of Geological Engineering, Beytepe, Ankara, Turkey, 5 General Directorate of MTA, Natural History Museum, Balgat, Ankara, Turkey, 6 Centre de Recherche sur la Paléobiodiversité et les Paléoenvironnements, Muséum National d’Histoire Naturelle, CNRS-UMR 7207, Paris, France
Abstract Top

Background
Preservation of fossil vertebrates in volcanic rocks is extremely rare. An articulated skull (cranium and mandible) of a rhinoceros was found in a 9.2±0.1 Ma-old ignimbrite of Cappadocia, Central Turkey. The unusual aspect of the preserved hard tissues of the skull (rough bone surface and brittle dentine) allows suspecting a peri-mortem exposure to a heating source.

Methodology/Principal Findings
Here we describe and identify the skull as belonging to the large two-horned rhinocerotine Ceratotherium neumayri, well-known in the late Miocene of the Eastern Mediterranean Province. Gross structural features and microscopic changes of hard tissues (bones and teeth) are then monitored and compared to the results of forensic and archaeological studies and experiments focusing on heating effects, in order to reconstruct the hypothetical peri-mortem conditions. Macroscopic and microscopic structural changes on compact bones (canaliculi and lamellae vanished), as well as partial dentine/cementum disintegration, drastic enamel-dentine disjunctions or microscopic cracks affecting all hard dental tissues (enamel, cementum, and dentine) point to continued exposures to temperatures around 400–450°C. Comparison to other cases of preservation of fossil vertebrates within volcanic rocks points unambiguously to some similarity with the 79 AD Plinian eruption of the Vesuvius, in Italy.

Conclusions/Significance
A 9.2±0.1 Ma-old pyroclastic density current, sourced from the Çardak caldera, likely provoked the instant death of the Karacaşar rhino, before the body of the latter experienced severe dehydration (leading to the wide and sustainable opening of the mouth), was then dismembered within the pyroclastic flow of subaerial origin, the skull being separated from the remnant body and baked under a temperature approximating 400°C, then transported northward, rolled, and trapped in disarray into that pyroclastic flow forming the pinkish Kavak-4 ignimbrite ~30 km North from the upper Miocene vent.

http://www.plosone.org/article/i ... l.pone.0049997.g002

犀牛資料:
Ceratotherium neumayri (Osborn, 1900) 諾氏白犀
年代: 中新世晚期
地點: 歐洲、亞洲地區

我的完整頭骨
http://www.fossilshk.com/forum/viewthread.php?tid=4215

[ 本帖最後由 Edmond 於 2012-11-29 06:04 PM 編輯 ]