Chaetocladus

{{Automatic taxobox

|fossil_range = Middle Ordovician - Devonian{{cite journal

| author = LoDuca, S.T. |author2=Kluessendorf, J. |author3=Mikulic, D.G.

| year = 2003

| title = A New Noncalcified Dasycladalean Alga From The Silurian Of Wisconsin

| journal = Journal of Paleontology

| volume = 77

| issue = 6

| pages = 1152–1158

| doi = 10.1666/0022-3360(2003)077<1152:ANNDAF>2.0.CO;2

|bibcode=2003JPal...77.1152L |s2cid=130113745 }}

| image = Chaetocladus_holotype_loduca1997.PNG

| image_caption = The holotype of Chaetocladus plumula (USNM 41 137, from LoDuca 1997)

| image_upright = 0.7

| taxon = Chaetocladus

| authority = Whitfield 1894 emend. LoDuca 1997

| subdivision_ranks = Species

| subdivision= See text.

}}

Chaetocladus is an extinct non-calcifying genus of unicellular green algae known from the Upper Silurian.

Morphology

Chaetocladus thalli range from 2–6 cm in height and average 1 cm in diameter. They comprise a parallel-sided, unbranching axis which is surrounded by leaf-like ramifications.

Fossil record

Chaetocladus is known from upper Silurian konservat lagerstätte, and found in association with other algae, arthropods, and annelid worms.{{cite journal

| author = LoDuca, S.T.

| year = 1997

| title = The Green Alga Chaetocladus (Dasycladales)

| journal = Journal of Paleontology

| volume = 71

| issue = 5

| pages = 940–949

| jstor=1306570

| doi = 10.1017/S0022336000035873

| bibcode = 1997JPal...71..940L

| s2cid = 130816541

}}

Similar Dasycladean algae are reported from late-Ordovician lagerstatte.{{cite journal

| year = 2007

| title = Exceptionally preserved Late Ordovician biotas from Manitoba, Canada

| journal = Geology

| volume = 35

| issue = 10

| pages = 883–886

| doi=10.1130/G23947A.1

|bibcode=2007Geo....35..883Y }}

Classification

Due to its morphological similarity to the extant order Dasycladales, Chaetocladus is considered to be an early cousin of this order. Unlike the majority of Dasycladales, Chaetocladus does not form deposit calcite - therefore it required much rarer taphonomic conditions to be preserved.{{cite journal

| author = Kenrick, P.

|author2=Vinther, J.

| year = 2006

| title = Chaetocladus gracilis n. sp., a non-calcified Dasycladales from the Upper Silurian of Skåne, Sweden

| journal = Review of Palaeobotany and Palynology

| volume = 142

| issue = 3–4

| pages = 153–160

| doi = 10.1016/j.revpalbo.2006.03.023

|bibcode=2006RPaPa.142..153K

}}

Some genera now recognised as Chaetocladus were originally described as Graptolites.e.g. {{cite journal