diff --git a/Changes b/Changes
index 205782a227..62420464d6 100644
--- a/Changes
+++ b/Changes
@@ -1,7 +1,12 @@
 10.7.x.x (relative to 10.7.3.0)
 ========
 
+Fixes
+-----
 
+- USD :
+  - Changed name of `ParticleField3DGaussianSplat` `radiance:sphericalHarmonicsCoefficients` primitive variables to end in `:$COEFFICIENT` instead of `[$COEFFICIENT]`.
+  - Changed Cortex type of `ParticleField3DGaussianSplat` `opacities` primitive variable to be `FloatVectorData` regardless of the incoming USD type (float or half).
 
 10.7.3.0 (relative to 10.7.2.0)
 ========
diff --git a/contrib/IECoreUSD/src/IECoreUSD/GaussianSplatAlgo.cpp b/contrib/IECoreUSD/src/IECoreUSD/GaussianSplatAlgo.cpp
index 52c1917a34..1b95ea6d5a 100644
--- a/contrib/IECoreUSD/src/IECoreUSD/GaussianSplatAlgo.cpp
+++ b/contrib/IECoreUSD/src/IECoreUSD/GaussianSplatAlgo.cpp
@@ -97,6 +97,19 @@ IECore::ObjectPtr readGaussianSplat( pxr::UsdVolParticleField3DGaussianSplat &sp
 	pxr::UsdAttribute opacitiesAttr;
 	splats.UsesFloatOpacities( &opacitiesAttr );
 	PrimitiveAlgo::readPrimitiveVariable( opacitiesAttr, time, newPoints.get(), "opacities" );
+	if( auto opacitiesHalfData = newPoints->variableData<HalfVectorData>( "opacities" ) )
+	{
+		// Cortex has HalfVectorData which supports half opacities. For consistency with
+		// other attributes and downstream clients, we convert to float.
+
+		const std::vector<half> &opacitiesHalf = opacitiesHalfData->readable();
+
+		FloatVectorDataPtr opacitiesData = new FloatVectorData();
+		opacitiesData->writable().insert( opacitiesData->writable().end(), opacitiesHalf.begin(), opacitiesHalf.end() );
+
+		PrimitiveVariable v = PrimitiveVariable( PrimitiveVariable::Interpolation::Vertex, opacitiesData );
+		newPoints->variables["opacities"] = v;
+	}
 
 	Canceller::check( canceller );
 	pxr::UsdAttribute degreeAttr = splats.GetRadianceSphericalHarmonicsDegreeAttr();
@@ -126,7 +139,7 @@ IECore::ObjectPtr readGaussianSplat( pxr::UsdVolParticleField3DGaussianSplat &sp
 				coefficients[j] = allCoefficients[j * coefficientCount + i];
 			}
 
-			newPoints->variables[fmt::format( "radiance:sphericalHarmonicsCoefficients[{}]", i )] = PrimitiveVariable( PrimitiveVariable::Interpolation::Vertex, coefficientsData );
+			newPoints->variables[fmt::format( "radiance:sphericalHarmonicsCoefficients:{}", i )] = PrimitiveVariable( PrimitiveVariable::Interpolation::Vertex, coefficientsData );
 		}
 	}
 
diff --git a/contrib/IECoreUSD/test/IECoreUSD/USDSceneTest.py b/contrib/IECoreUSD/test/IECoreUSD/USDSceneTest.py
index 15713f38e1..1506d96fae 100644
--- a/contrib/IECoreUSD/test/IECoreUSD/USDSceneTest.py
+++ b/contrib/IECoreUSD/test/IECoreUSD/USDSceneTest.py
@@ -5175,7 +5175,7 @@ def testReadGaussianSplats( self ) :
 					( "P", IECore.V3fVectorData, IECore.GeometricData.Interpretation.Point, 4 ),
 					( "orientations", IECore.QuatfVectorData, None, 4 ),
 					( "scales", IECore.V3fVectorData, IECore.GeometricData.Interpretation.Numeric, 4 ),
-					( "opacities", IECore.FloatVectorData if sceneFile == "gaussianSplatsFloat.usda" else IECore.HalfVectorData, None, 4 ),
+					( "opacities", IECore.FloatVectorData, None, 4 ),
 					( "radiance:sphericalHarmonicsDegree", IECore.IntData, None, None ),
 				] :
 					with self.subTest( variable = variable ) :
@@ -5186,7 +5186,7 @@ def testReadGaussianSplats( self ) :
 							self.assertEqual( len( splats[variable].data ), vectorLength )
 
 				for i in range( 0, 4 ) : # degree = 1, count = ( degree + 1 ) * ( degree + 1 )
-					variable = "radiance:sphericalHarmonicsCoefficients[{}]".format( i )
+					variable = "radiance:sphericalHarmonicsCoefficients:{}".format( i )
 					self.assertIsInstance( splats[variable].data, IECore.V3fVectorData )
 					self.assertEqual( splats[variable].data.getInterpretation(), IECore.GeometricData.Interpretation.None_ )
 					self.assertEqual( len( splats[variable].data ), 4 )