Limits...
Description of a Well Preserved Fetus of the European Eocene Equoid Eurohippus messelensis.

Franzen JL, Aurich C, Habersetzer J - PLoS ONE (2015)

Bottom Line: The postcranial fetal skeleton is almost complete and largely articulated, allowing the conclusion that the pregnant mare was in late gestation.The apparent intrauterine position of the fetus is normal for the phase of pregnancy.Death of mare and fetus were probably not related to problems associated with parturition.

View Article: PubMed Central - PubMed

Affiliation: Department Messelforschung, Senckenberg Forschungsinstitut Frankfurt, Frankfurt am Main, Germany; Department Geowissenschaften, Naturhistorisches Museum Basel, Basel, Switzerland.

ABSTRACT
The early Middle Eocene locality of Grube Messel, near Darmstadt (Germany), is famous for its complete vertebrate skeletons. The degree of preservation of soft tissues, such as body silhouettes, internal organs and gut contents, is frequently remarkable. The present specimen was analyzed for remnants of the reproductive system. Classic anatomy and osteology and high-resolution micro-x-ray were applied to describe the fetus of the European Eocene equoid Eurohippus messelensis. Scanning electronic microscopy (SEM) was used for determination of soft tissue remnants. The fetus is the earliest and best-preserved fossil specimen of its kind. The postcranial fetal skeleton is almost complete and largely articulated, allowing the conclusion that the pregnant mare was in late gestation. The apparent intrauterine position of the fetus is normal for the phase of pregnancy. Death of mare and fetus were probably not related to problems associated with parturition. Soft tissue interpreted as the uteroplacenta and a broad uterine ligament are preserved due to bacterial activity and allow considerations on the evolutionary development of the structures.

No MeSH data available.


Related in: MedlinePlus

Identification of the uteroplacenta.The photograph of the original upper side of the fossil horse was taken before transfer into epoxy resin during preparation. It displays a black shadow (edged in white) covering the fetus. Arrows point to wrinkling structures, which appeared on the external wall of the uterine horn after accidental rupture. Scale = 5 cm. Right upper corner: for orientation, the outline of the uteroplacenta is shown on a micro-x-ray of the whole skeleton of the mare.—Photo: Senckenberg Forschungsinstitut Frankfurt, Sven Tränkner; micro-x-ray: Senckenberg Forschungsinstitut Frankfurt, Jörg Habersetzer.
© Copyright Policy
Related In: Results  -  Collection

License
getmorefigures.php?uid=PMC4622040&req=5

pone.0137985.g007: Identification of the uteroplacenta.The photograph of the original upper side of the fossil horse was taken before transfer into epoxy resin during preparation. It displays a black shadow (edged in white) covering the fetus. Arrows point to wrinkling structures, which appeared on the external wall of the uterine horn after accidental rupture. Scale = 5 cm. Right upper corner: for orientation, the outline of the uteroplacenta is shown on a micro-x-ray of the whole skeleton of the mare.—Photo: Senckenberg Forschungsinstitut Frankfurt, Sven Tränkner; micro-x-ray: Senckenberg Forschungsinstitut Frankfurt, Jörg Habersetzer.

Mentions: As indicated by the compact ellipsoid accumulation of articulated fetal bones that are nearly in the original position, the fetus was still enwrapped in the uteroplacenta (pregnant uterus, lined by the allantochorion) when the carcass fell to the bottom of the Eocene Lake Messel. Photographs of the original upper side of the fossil before transfer into epoxy resin (during preparation; see [12]) show that the fetus was covered by a black shadow (Fig 7). At Messel, such black shadows are typical of preserved soft tissue [13–14], although we are not dealing with direct preservation but with a by-product of bacterial metabolism. In the Eocene Lake Messel, bacterial decomposition of soft tissue produced carbon dioxide, which reacted with dissolved iron from the lake water to precipitate iron carbonate minerals. The bacteria became coated with a thin layer of Fe-carbonate (siderite) and autolithified. A thin and porous bacterial mat developed, which exactly followed the lines of contact between the decomposing soft tissue and the sediment. The mat was subsequently infiltrated by organic material (e.g. kerogene), staining it black [14].


Description of a Well Preserved Fetus of the European Eocene Equoid Eurohippus messelensis.

Franzen JL, Aurich C, Habersetzer J - PLoS ONE (2015)

Identification of the uteroplacenta.The photograph of the original upper side of the fossil horse was taken before transfer into epoxy resin during preparation. It displays a black shadow (edged in white) covering the fetus. Arrows point to wrinkling structures, which appeared on the external wall of the uterine horn after accidental rupture. Scale = 5 cm. Right upper corner: for orientation, the outline of the uteroplacenta is shown on a micro-x-ray of the whole skeleton of the mare.—Photo: Senckenberg Forschungsinstitut Frankfurt, Sven Tränkner; micro-x-ray: Senckenberg Forschungsinstitut Frankfurt, Jörg Habersetzer.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4622040&req=5

pone.0137985.g007: Identification of the uteroplacenta.The photograph of the original upper side of the fossil horse was taken before transfer into epoxy resin during preparation. It displays a black shadow (edged in white) covering the fetus. Arrows point to wrinkling structures, which appeared on the external wall of the uterine horn after accidental rupture. Scale = 5 cm. Right upper corner: for orientation, the outline of the uteroplacenta is shown on a micro-x-ray of the whole skeleton of the mare.—Photo: Senckenberg Forschungsinstitut Frankfurt, Sven Tränkner; micro-x-ray: Senckenberg Forschungsinstitut Frankfurt, Jörg Habersetzer.
Mentions: As indicated by the compact ellipsoid accumulation of articulated fetal bones that are nearly in the original position, the fetus was still enwrapped in the uteroplacenta (pregnant uterus, lined by the allantochorion) when the carcass fell to the bottom of the Eocene Lake Messel. Photographs of the original upper side of the fossil before transfer into epoxy resin (during preparation; see [12]) show that the fetus was covered by a black shadow (Fig 7). At Messel, such black shadows are typical of preserved soft tissue [13–14], although we are not dealing with direct preservation but with a by-product of bacterial metabolism. In the Eocene Lake Messel, bacterial decomposition of soft tissue produced carbon dioxide, which reacted with dissolved iron from the lake water to precipitate iron carbonate minerals. The bacteria became coated with a thin layer of Fe-carbonate (siderite) and autolithified. A thin and porous bacterial mat developed, which exactly followed the lines of contact between the decomposing soft tissue and the sediment. The mat was subsequently infiltrated by organic material (e.g. kerogene), staining it black [14].

Bottom Line: The postcranial fetal skeleton is almost complete and largely articulated, allowing the conclusion that the pregnant mare was in late gestation.The apparent intrauterine position of the fetus is normal for the phase of pregnancy.Death of mare and fetus were probably not related to problems associated with parturition.

View Article: PubMed Central - PubMed

Affiliation: Department Messelforschung, Senckenberg Forschungsinstitut Frankfurt, Frankfurt am Main, Germany; Department Geowissenschaften, Naturhistorisches Museum Basel, Basel, Switzerland.

ABSTRACT
The early Middle Eocene locality of Grube Messel, near Darmstadt (Germany), is famous for its complete vertebrate skeletons. The degree of preservation of soft tissues, such as body silhouettes, internal organs and gut contents, is frequently remarkable. The present specimen was analyzed for remnants of the reproductive system. Classic anatomy and osteology and high-resolution micro-x-ray were applied to describe the fetus of the European Eocene equoid Eurohippus messelensis. Scanning electronic microscopy (SEM) was used for determination of soft tissue remnants. The fetus is the earliest and best-preserved fossil specimen of its kind. The postcranial fetal skeleton is almost complete and largely articulated, allowing the conclusion that the pregnant mare was in late gestation. The apparent intrauterine position of the fetus is normal for the phase of pregnancy. Death of mare and fetus were probably not related to problems associated with parturition. Soft tissue interpreted as the uteroplacenta and a broad uterine ligament are preserved due to bacterial activity and allow considerations on the evolutionary development of the structures.

No MeSH data available.


Related in: MedlinePlus