Ammonoid Taphonomy This chapter reviews the ammonoid taphonomy, especially focusing on recent advances in various methodologies (including new data on necrosis and fossil diagenesis of organic components and experimenta...

Chapter 2.20 by Wani & Gupta reviewed understudied #Ammonoid #Taphonomy: rdcu.be/eQSvE

Latest highlight isolated soft parts and septa, postmortem drift potential and value:
rdcu.be/eQStN
doi.org/10.18261/let...
doi.org/10.7717/peer...
rdcu.be/eQSuj
doi.org/10.1080/0891...
doi.org/10.1016/j.cr...

Ammonoid Biostratigraphy in the Jurassic In the Jurassic, ammonoids showed the most rapid evolution and thus are successfully used as tools for subdividing and dating marine sediments of this period. Evolutionary driven morphological shifts ...

Chapter 2.14 by Schweigert on #Ammonoid #Biostratigraphy in the #Jurassic: doi.org/10.1007/978-...

remains key for high-resolution biochronology on regional levels: doi.org/10.1111/let....
dx.doi.org/10.7306/VJ.2...

but is increasingly supplemented by other methods: doi.org/10.1144/SP46...

Paleozoic Ammonoid Biostratigraphy The time interval between the Emsian (Early Devonian) and the end of the Permian is characterized by the rapid evolution of the Ammonoidea, and this evolution is reflected by the establishment of a de...

Chapter 2.12 by Korn & Klug on #Paleozoic #Ammonoid #Biostratigraphy: rdcu.be/eNqlc

remaining of key importance for regional #correlation and stratigraphy: doi.org/10.1144/SP51... doi.org/10.1007/s125... doi.org/10.1016/j.an... doi.org/10.22201/igl... doi.org/10.1007/s125... doi.org/10.1007/s125...

Redirecting

The #ammonoid fauna, rich in Sonniniidae (in)famous for the large intraspecific variation (doi.org/10.5252/geod...), contributes to our understanding their #evolution across the Aalenian–Bajocian transition. Collected #belemnites have major paleobiogeographic significance: doi.org/10.1016/j.ge...

Ammonoid Paleopathology We herein review fossil examples of pathological phenomena and present a historical review, definition, and the taxonomic handling of such anomalies (forma aegra concept, symptom vs. syndrome). The described phenomena are separated in those with exogenic (injuries,...

21th chapter by Hoffmann & Keupp reviews the long #history of #ammonoid #paleopathology doi.org/10.1007/978-...

New reports fill #gaps in our #knowledge:
doi.org/10.1007/s125...
doi.org/10.7717/peer...
doi.org/10.4202/app....
doi.org/10.5710/AMGH...
doi.org/10.5194/fr-2...
doi.org/10.18261/let...

Isotope Signature of Ammonoid Shells Geochemical analyses of ammonoid shells provide an independent and objective data set to evaluate life and habitat of the animal. This uniformitarian consideration, in combination with functional morphology and physical evidence for ecology or physiology, potentially...

19th chapter by Moriya on #Isotope Signature of #Ammonoid #Shells: rdcu.be/eJqoP

Their interpretation remains controversial today:
doi.org/10.1016/j.cr...
doi.org/10.1111/pala...

New approaches (doi.org/10.1017/pab....) and #modelling (doi.org/10.1007/s133...)
may however help in this endeavour.

Stable isotopes and predation marks shed new light on ammonoid habitat depth preferences - Scientific Reports Scientific Reports - Stable isotopes and predation marks shed new light on ammonoid habitat depth preferences

18th chapter by Lukeneder constrained #Ammonoid #Habitats and #Life History: rdcu.be/eJqnW

This remains tricky and only doable with a multi-proxy approaches combining #morphology, #geochemistry, #modelling and facies analysis:
doi.org/10.1038/s415...
doi.org/10.1080/0311...
doi.org/10.1007/978-...

Hydromechanics of ammonoid conch ornamentation: trade-offs between rocking attenuation and drag reduction | Paleobiology | Cambridge Core Hydromechanics of ammonoid conch ornamentation: trade-offs between rocking attenuation and drag reduction

17th chapter by Naglik et al. focuses on #Ammonoid #Locomotion: rdcu.be/eJqhf

Latest studies use #biomimetic models (doi.org/10.1093/iob/...
; doi.org/10.1038/s415...) or #Computational fluid dynamics (doi.org/10.26879/956).

#tradeoffs are key: doi.org/10.4202/app....
doi.org/10.1017/pab....

Ammonoid Buoyancy The buoyancy of ammonoids is one of the most controversial issues of ammonoid paleobiology. This chapter gives a short historical review about attempts made to clarify the potential function of the cephalopod chambered shell (phragmocone) and ammonoid life habits...

16th chapter by Hoffmann et al. reviews #Ammonoid #Buoyancy: rdcu.be/eJqeH

New methods show even the oldest and oddest ammonoids neutral buoyancy and #life orientation: doi.org/10.1111/let.... doi.org/10.1016/j.ge...
doi.org/10.1371/jour...
doi.org/10.1038/s415...
doi.org/10.1017/pab....

Key innovations in Mesozoic ammonoids: the multicuspidate radula and the calcified aptychus A nearly complete radula with seven elements per row preserved inside of an isolated, bivalved, calcitic lower jaw (= aptychus) of the Late Jurassic ammonite Aspidoceras is described from the Fossill...

11th chapter by Kruta et al. reviews the #Ammonoid #Radula: rdcu.be/eJgIw

These #feeding structures date back to the #Cambrian:
doi.org/10.3140/bull...

Its modification led to calcified lower #jaws in derived ammonoids: doi.org/10.1111/pala...

Not all #chitinous hooks are radular: rdcu.be/eJgHQ

Ammonoid Buccal Mass and Jaw Apparatus Current knowledge on the ammonoid buccal mass and jaw apparatus is synthesized based on in situ fossil records from 109 genera that are distributed in 30 superfamilies of 8 suborders of Devonian to Cretaceous age. As in those of modern cephalopods, the jaw apparatus...

10th chapter by Tanabe et al. reviews #Ammonoid #Buccal #Mass and #Jaw #Apparatus: doi.org/10.1007/978-...

New jaw studies implies that:
chitinous mandibles were present at the origin of the whole clade: doi.org/10.1111/pala...

#squid radiation before ammonoid #extinction: doi.org/10.1126/scie...

Goniatites sphaericus (Sowerby, 1814), the archetype of Palaeozoic ammonoids: a case of decreasing phenotypic variation through ontogeny - PalZ The Late Viséan (Early Carboniferous) ammonoid species Goniatites sphaericus (Sowerby, 1814) is revised with the use of the type material. With respect to conch morphology, suture line and particularly shell ornament, it is regarded as a senior synonym of the species Goniatites fimbriatus (Foord and Crick, 1897) and must therefore be re-established as an important index fossil for the ammonoid stratigraphy of the Rhenohercynian and Subvariscan shelves. The Goniatites fimbriatus Zone has been re-named Goniatites sphaericus Zone on this basis. The study of ontogenetic changes in the conch parameters shows that intraspecific variation occurs within a wide range. In the whorl profile, variation is very high in small juveniles, while in the coiling rate, intermediate growth stages are more strongly affected.

9th chapter by De Baets et al. reviews #Ammonoid #Intraspecific #Variability: doi.org/10.1007/978-...

New studies corroborate high variation in early-middle stages: doi.org/10.1007/s125...
doi.org/10.1017/pab....
or important ecophenotypic variation:
doi.org/10.1017/pab....
doi.org/10.1206/3922.1

First direct evidence of ammonoid ovoviviparity Ammonoids had high evolutionary rates and diversity throughout their entire history and played an important role in the high-resolution sub-division of the Mesozoic, but much of their palaeobiology re...

5th chapter by me, Landman & Tanabe summarised our understanding of #ammonoid #embryonic #development: doi.org/10.1007/978-...

Spectacular discoveries further constrain their #reproductive strategies: doi.org/10.1111/let....
doi.org/10.7717/peer...
dx.doi.org/10.4202/app....
doi.org/10.1017/pab....

Cameral Membranes, Pseudosutures, and Other Soft Tissue Imprints in Ammonoid Shells Ammonoids occasionally show subtle structures linked with the attachment or contact of the soft body with the shell. Only some of these structures were mineralized and thus are rarely preserved. We describe mainly three different kinds of structures, namely (i)...

4th chapter by Polizzotto et al. summarised the knowledge on #Cameral #Membranes, #Pseudosutures, and Other Soft #Tissue Imprints in #Ammonoid Shells: doi.org/10.1007/978-...

New discoveries may help to explain their formation: link.springer.com/article/10.1...; doi.org/10.2110/palo...

Fractal-like geometry as an evolutionary response to predation? Fractal-like shapes of ammonoid septa provide the animals with enhanced structural stability and protection against predation.

3rd chapter by Klug & Hoffmann reviewed “ #Ammonoid septa and sutures ”: doi.org/10.1007/978-...

The structure (doi.org/10.1038/s415...) and function of their #septa and #sutures (doi.org/10.1126/scia...) continue to be an area of ongoing and fascinating #research.

Ammonoid Color Patterns Color patterns on ammonoid cephalopods are rarely preserved despite the fact that millions of the shells of these extinct animals have been recovered from Devonian through the Upper Cretaceous rocks that were deposited in a wide variety of marine environments around...

2nd chapter by Mapes & Larson dealt with “ #Ammonoid #Color #Patterns”: doi.org/10.1007/978-...

In the meantime, additional fake and true color patterns have been found in #ammonoids (doi.org/10.1111/brv....) and #nautiloids (doi.org/10.54103/203...).

1st chapter by Klug et al. (2015) dealt with technical #terms and #qualitative to #quantitative aspects when "Describing #Ammonoid Conchs": doi.org/10.1007/978-...

Recommendations seem to have been embraced in Paleozoic (doi.org/10.5252/geod...) to Mesozoic (doi.org/10.1016/j.cr...) communities

Ammonoid Paleobiology: From anatomy to ecology This two-volume work is a testament to the abiding interest and human fascination with ammonites. We offer a new model to explain the morphogenesis of septa and the shell, we explore their habitats by the content of stable isotopes in their shells, we discuss the origin and later evolution of this important clade, and we deliver hypotheses on its demise. The Ammonoidea produced a great number of species that can be used in biostratigraphy and possibly, this is the macrofossil group, which has been used the most for that purpose. Nevertheless, many aspects of their anatomy, mode of life, development or paleobiogeographic distribution are still poorly known. Themes treated are biostratigraphy, paleoecology, paleoenvironment, paleobiogeography, evolution, phylogeny, and ontogeny. Advances such as an explosion of new information about ammonites, new technologies such as isotopic analysis, tomography and virtual paleontology in general, as well as continuous discovery of newfossil finds have given us the opportunity to present a comprehensive and timely "state of the art" compilation. Moreover, it also points the way for future studies to further enhance our understanding of this endlessly fascinating group of organisms.

10 years ago, our co-edited Topics in Geobiology volumes on #Ammonoid #Paleobiology came out:

From anatomy to ecology:
doi.org/10.1007/978-...
From macroevolution to paleogeography: doi.org/10.1007/978-...

In the last months of 2025, i will explore new discoveries on these topics in a thread:

Ammonit fosili değil, Doğubank merdiveni.

#suriçimerdivenleri #ammonit #ammonoidea #ammonoid #fosil #sirkeci #doğubank #garantisibenimkardeşim

Longitudinal median section through the well preserved specimen PIMUZ 28583 of Sellanarcestes spp. (Sellanarcestes wenkenbachi Zone, Emsian, Oufrane, Morocco) displaying many “Housean pits” interpreted as blister pearls, many with internal tube.

The answer is both fossil types are #underdogs to study #evolution and i discovered parasitic remains in #ammonoid shell pathologies during my PhD research: doi.org/10.4202/app..... I saw the potential in both; one things led to another. Now i am a #malacologist and a #paleoparasitologist

A large (~10 cm X 15cm) "antique" glass-mounted thin section through a concretionary nodule ("bullion") shows dozens of small planispirally coiled and chambered shells clustered randomly together. The shells are in various orientations with respect to the plane of the section. In most, the inner whorls appear clear, with sediment or secondary mineral-fill in the outer (body chamber) portion. The irregularly shaped surrounding rock matrix is very dark in contrast. The roughly rectangular cover slip shows a thin rim of amber coloured adhesive. On the right side of the section, a scale graduated in millimetres indicates the overall size. A small circular label in the lower right reads, "JAMES LOMAX - PETROLOGIST" around the outer margin and, "MOSES GATE - BOLTON" in the centre. In the upper right, a small typed label ("No. 2.") is affixed. The section was likely produced sometime in the late 1800's or early 1900's.

A close-up view of the thin section showing details of the very small coiled goniatite shells.

Historic Lomax #thinsection of a classic marine "bullion" concretion from the Upper #Carboniferous (~310 MYA) of Lancashire, UK, reveals dozens of tiny #fossil juvenile & embryonic ("ammonitella") #goniatite shells in an organic-rich carbonate matrix. #MolluscMonday #ammonoid #cephalopods

[Review] Ammonoid - Pierce The Veil EP The Ammonoid project was born in 2022, with a lineup that unites the two coasts of the USA exploring Progressive Doom sounds steeped in Psychedelia.

[Review] Ammonoid - Pierce The Veil EP

progrockjournal.com/review-ammon...

#progrockjournal #review #ammonoid #debut #dbutalbum #progressive #doom #psychedelia #music

Rough digital paint sketch of a sea creature with a coiled shell like a nautilus, and head like a squid. The shell is beige and orange, the head is pink, purple and blue. The rest of the scene is a blue underwater reef.

My #ADHD brain got distracted while looking for a paper and did some work on this. #InvertFest #Goniatite #Ammonoid #Cephalopod.

Redirecting

🐚 #Fossilfriday🌀 #Ammonoid research using new index reveals that taxa with complex ornamentation have higher origination/extinction rates 📈 and shorter evolutionary ranges 📉 than simpler forms. #Complexity drives rapid #Evolution and increased #Extinction! #Paleontology dx.doi.org/10.1016/j.cu...